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Fix RPC Server Errors in Windows: Quick Troubleshooting Guide

Learn how to quickly diagnose and resolve the RPC server error in Windows that stops backups, printers, and logins. Follow our guide to restore network harmony.

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Fix RPC Server Errors in Windows: Quick Troubleshooting Guide

When a backup stalls midway or a printer won’t print, the frustration is immediate. That’s usually the RPC server error, a cryptic message that can bring an entire network to a halt like a traffic jam. Ever wondered why one service can become the choke point of your IT ecosystem? We’re about to pull back the curtain and show you how to break that cycle.

The RPC Service: Windows’ Silent Conductor

RPC—Remote Procedure Call—lets one computer run code on another as if it were local. Think of it as a conductor guiding an orchestra of services, keeping harmony across machines. When the conductor stops, the whole symphony falls silent. That’s why the RPC server error can feel like a blackout in a data center. It can lock out backups, block printer installations, freeze remote disk management, and even prevent log‑ons. IT teams often scramble, waiting for a technician to reboot a service that should be running. The stakes are high: lost productivity, delayed compliance, and a widening security gap. But you don’t have to stay stuck; the fix is often a few clicks away. In the sections that follow, we’ll walk through step‑by‑step fixes for Veeam, disk management, and printers. You’ll get a practical checklist, real‑world examples, and a confidence boost that your network will run smoother. Ready to turn that silent bottleneck into a humming highway? Let’s dive in.

RPC errors pop up during login, backup, or printing, causing hiccups to outages daily. When the RPC service stops, any application that relies on it—whether Microsoft’s own tools or third‑party software—falls into a state of limbo. That’s why we’ve compiled a guide to troubleshoot RPC server is unavailable in Windows, cutting through noise and giving steps. Confirm the RpcSs service is running; a stopped RPC service is a common culprit in your environment for most cases. Next, check the firewall. Windows Firewall and many third‑party solutions block the dynamic RPC port range, typically 49152‑65535. A misconfigured DNS can make a machine unreachable, triggering the same error across the network for all connected clients today. We’ll dive into Veeam, disk management, and printer scenarios, each with a tailored checklist to help you fix. Each checklist pinpoints the root cause faster than a generic restart approach without wasting hours of downtime. With this foundation, you’ll read the error, understand the cause, and apply the right fix before the outage spreads swiftly. This ripple effect can cascade, turning a single misstep into a network‑wide crisis for all users.

Learn more about Windows networking | Microsoft Support: RPC Server Unavailable

Quick Troubleshooting Checklist

  • Verify the RpcSs service is running.
  • Ensure Windows Firewall allows dynamic RPC ports (49152–65535).
  • Confirm DNS resolution for the server is correct.
  • Restart the RPC service or reboot the machine if necessary.
  • Verify network connectivity between client and server.
  • Re‑run the operation that triggered the error to confirm resolution.

What Is RPC and Why It Matters

Remote Procedure Call (RPC) lets a program on one computer run code on another machine as if it were local. In Windows, RPC underpins a lot of services—Active Directory, Remote Desktop, Windows Update, Veeam backups, printer installation, and disk management. When RPC fails, a single “RPC server unavailable” error can turn into a full‑blown system crisis.

Common Causes of “RPC Server Unavailable”

  • Disabled or stopped RPC services (RpcSs or RpcLocator)
  • Firewall blocking the dynamic port range (TCP 49152‑65535)
  • DNS resolution failures or incorrect host names
  • Time skew between client and server
  • Antivirus or third‑party security software interfering with RPC traffic
  • Network connectivity problems (e.g., broken cables, misconfigured switches)

Step‑by‑Step Fixes

1. Verify and Start the RPC Services

  1. Open Services (services.msc).
  2. Find Remote Procedure Call (RPC) (RpcSs) and RPC Locator.
  3. Set both to Automatic and click Start if they’re stopped.
  4. Make sure the RPC Endpoint Mapper is running too.

2. Check the Firewall Rules

  1. Open Windows Defender Firewall with Advanced Security.
  2. Create or enable a rule that allows TCP ports 49152‑65535 inbound and outbound.
  3. Confirm the rule applies to the right profiles (Domain, Private, Public).

3. Resolve DNS Issues

  1. Run nslookup <server-name> to see if the name resolves to the right IP.
  2. If it doesn’t, update the DNS entry or use the IP address directly in the application.

4. Synchronize Time

  1. Make sure both client and server clocks are in sync (use NTP or the Windows Time service).
  2. If the skew is greater than 5 minutes, correct the clock and try again.

5. Disable Interfering Security Software

  1. Temporarily turn off antivirus or endpoint protection.
  2. Test the RPC connection.
  3. If the problem goes away, add an exception for RPC traffic.

6. Test Connectivity

  1. From the client, run ping <server-ip> and tracert <server-ip> to confirm reachability.
  2. Verify that no network devices block the dynamic port range.

Quick Checklist

Further Reading

When the “RPC server unavailable” message pops up, it feels like a traffic jam in your network. We’re not just chasing a typo; we’re diagnosing the heart of Windows communication. Why does a single error ripple through backups, printers, and remote desktops? Let’s break it down.

What is RPC?

RPC (Remote Procedure Call) is a core Windows networking component that lets processes on different machines talk as if they were local. It powers file sharing, printer sharing, domain authentication, and many third‑party applications across the network. Without a functioning RPC service, remote management tasks and network‑dependent operations fail.

Root Causes Map

Cause

Typical Symptoms

Key Services Affected

Disabled RPC services

Log‑on stalls, remote desktop fails

RpcSs, RpcLocator

Firewall blocks

Dynamic port errors, Veeam failures

Windows Firewall, third‑party firewalls

DNS misconfigurations

Remote host not found, “server not found”

DNS, NetBIOS Helper

Time skew

Domain auth errors, replication lag

w32time

Antivirus interference

Veeam jobs hang, service restarts

Veeam services

Dynamic port range misconfig

Agent cannot bind ports

RPC dynamic port range

1. Disabled Services

  • Symptoms: Error during log‑on or remote management.
  • Fix: Open Services, set Remote Procedure Call (RPC) and RPC Locator to Automatic, then start.
  • Why it matters: These are the backbone; without them, no remote call works.

2. Firewall Blocks

  • Symptoms: Operations that use high ports fail.
  • Fix: Make sure TCP 49152‑65535 is allowed; add an exception for SMB (TCP 139, 445, UDP 137‑138).
  • Why it matters: Firewalls block the dynamic dance of RPC.

3. DNS Issues

  • Symptoms: “Server not found” during network tasks.
  • Fix: Verify hostnames resolve with nslookup; correct DNS records or switch to a reliable DNS server.
  • Why it matters: RPC relies on name resolution to locate services.

4. Time Skew

  • Symptoms: Authentication failures, replication errors.
  • Fix: Run w32time /resync on all machines; make sure the domain controller time is correct.
  • Why it matters: RPC timestamps must match; otherwise, the handshake fails.

5. Antivirus Interference

  • Symptoms: Veeam backups or other services hang.
  • Fix: Exclude Veeam directories and RPC processes from real‑time scanning.
  • Why it matters: Some AV tools mistakenly block RPC traffic.

6. Dynamic Port Range Misconfig

  • Symptoms: Temporary agents cannot bind to ports.
  • Fix: Reset to default with netsh int ipv4 set dynamicport tcp start=49152 num=16384.
  • Why it matters: RPC needs a predictable port range to negotiate.

Systematic Isolation Playbook

  1. Check services on both client and server.
  2. Audit firewall rules for RPC and SMB.
  3. Validate DNS with ping and nslookup.
  4. Sync clocks using the domain controller.
  5. Review antivirus logs for blocked RPC.
  6. Confirm port range is intact.
  7. Re‑run the operation and observe.

Real‑World Scenarios

  • Veeam Backups – Make sure RPC is running on the Veeam server and the target VM; add firewall exceptions for port 443 and 5985.
  • Printer Installations – Verify RPC and SMB services on the print server; check DNS resolution for the printer name.
  • Disk Management – When mounting volumes or running CHKDSK, RPC must be available on the host; a disabled RPC service will trigger “RPC server unavailable” errors during volume operations.

Checklist

For more detailed guidance, see our Windows Networking Guide or consult the official Microsoft article on troubleshooting RPC server errors: Microsoft support – Troubleshoot RPC server unavailable.

Fixing the Error in Veeam Backup & Replication

1. Understanding RPC

Remote Procedure Call (RPC) is a core Windows networking service that lets applications on different computers talk to one another. The RPC Server (RpcSs) runs as a Windows service and is required for many system functions—Veeam backup, disk management, printer installation, you name it. When the RPC service stops, a firewall blocks it, or the system clock drifts, Windows will shout back with “RPC server unavailable”.

2. Common Causes

  • RPC Service stopped or disabled – the RpcSs service is not running.
  • Firewall blocks dynamic ports – the 49152‑65535 range is not allowed.
  • DNS resolution problems – hostnames cannot be resolved.
  • Time skew – the backup server and target hosts have clocks that differ by more than 5 minutes.
  • Other services dependent on RPC – such as VeeamVSSSupport, Windows Management Instrumentation, or printer spooler.

3. Quick‑Check Checklist

Step

What to Verify

Tool / Command

RPC Service

RpcSs running

Services.msc

Firewall

Exclusion for 49152‑65535

Windows Firewall UI

Time

<5‑minute skew

w32time /resync

DNS

Proper resolution

nslookup <hostname>

4. Troubleshooting Scenarios

4.1 Veeam Backup & Replication

  1. Firewall Exclusions
  • Add an inbound rule for TCP 49152‑65535 named Veeam Backup.
  • Command:
bash
1netsh advfirewall firewall add rule name="Veeam Backup" dir=in action=allow protocol=TCP localport=49152-65535
  1. VeeamVSSSupport Service
  • Start the service if it’s stopped.
  • If it’s corrupted, delete the service and folder:
bash
1sc delete VeeamVSSSupport
2     rmdir /S /Q "C:\\Windows\\VeeamVSSSupport"
  1. Sync Time & DNS
  • Run w32time /resync on the backup server and all target hosts.
  • Check DNS with nslookup <hostname>.
  1. Verify RPC
  • Open Event Viewer → Windows Logs → System and look for RpcSs or RpcLocator errors.
  • If the errors keep coming, restart the RpcSs service.

4.2 Disk Management

  1. Enable RPC Service
  • In Services.msc, set RpcSs to Automatic and start it.
  1. Firewall
  • Allow dynamic ports 49152‑65535 as shown above.
  1. Time & DNS
  • Follow the same steps as in the Veeam section.
  1. Test Disk Operations
  • Try creating a new volume or extending a partition; if RPC errors pop up, revisit the checklist.

4.3 Printer Installation

  1. RPC Service – make sure it’s running.
  2. Firewall – allow dynamic ports.
  3. Time & DNS – sync clocks and verify resolution.
  4. Install Printer – use the Add a printer wizard; if it reports RPC errors, check the event logs for RpcSs failures.

5. Resources

6. Checklist Summary

Follow these steps in order; once all items are verified, the “RPC server unavailable” error should be resolved.

Clicking “Connect” to a remote disk and seeing “RPC server is unavailable” tells you something’s off. The message feels like a red flag on a highway, blocking volume management, VM creation, and even printing. Let’s dig into why it happens and how to fix it.

RPC, or Remote Procedure Call, is the backbone that lets Windows services talk across machines. Without it, even simple tasks like disk management break. Think of RPC as the conductor of a symphony of processes; when the conductor stops, the whole orchestra falls silent.

Common culprits include:

  • RpcSs or RpcLocator stopped – the core services that enable remote calls.
  • Firewall blocking dynamic ports 49152‑65535 – the range RPC uses for communication.
  • DNS or NetBIOS name resolution errors – the host name can’t be found.
  • Time drift between host and client – clocks out of sync break authentication.
  • Antivirus interference – security software may block RPC traffic.

First, open Services.msc. Locate Virtual Disk Service (VDS) and set its startup type to Automatic. Then start it; if it fails, consult the event logs for clues. This step guarantees the disk engine can talk remotely.

Next, add a rule for Remote Volume Management. In Windows Firewall, create an inbound rule called “Remote Volume Management” that allows TCP 49152‑65535. You can temporarily disable the firewall to see if the error disappears; if it does, the rule was missing. Just remember to turn the firewall back on.

Make sure the admin account has Disk Management rights on the target. For Hyper‑V, the host and manager need to be in a trusted domain or workgroup. Without those permissions, RPC will still complain, even if the services are up.

Both the client and host must run RpcSs and RpcLocator. Open Services.msc on each machine and set those services to Automatic.

Test the network path with PowerShell:

typescript
1Test‑NetConnection -ComputerName host -Port 445

If it passes, the route is clear; if it fails, look into firewall or routing problems.

Forums such as TenForums and ServerFault host real‑world scripts. Microsoft Docs offer official guidance on RPC troubleshooting. Bookmark those links—they’re lifesavers when you hit a wall.

Checklist

Step

Action

1

Restart RpcSs and RpcLocator on both machines

2

Enable VDS and set to Automatic

3

Add firewall rule for TCP 49152‑65535

4

Verify Disk Management permissions

5

Test connectivity with Test-NetConnection

6

Re‑run the remote operation

Ready to put these steps into action? Let’s keep going.

What Is the RPC Service?

If you’re troubleshooting an “RPC server is unavailable” error in Windows, this guide will help you resolve the issue quickly.

Remote Procedure Call (RPC) is the backbone of Windows networking. It lets applications and services on one computer call functions on another as if they were local. The RPC server (RpcSs) listens for these calls and dispatches them to the appropriate service. Without a running RPC service, many network functions—including printer sharing—cannot be established.

Common Causes of “RPC Server Unavailable”

  • Disabled or stopped RPC services (RpcSs, RpcLocator, Print Spooler)
  • Blocked SMB ports (TCP 139, 445; UDP 137, 138)
  • DNS resolution problems that prevent the client from finding the printer’s name
  • Firewall or security software that blocks RPC traffic

Step‑by‑Step Fixes

  1. Verify Service Status – Open services.msc and make sure RpcSs, RpcLocator, and Print Spooler are set to Automatic and started.
  2. Open SMB Ports – In Windows Firewall, allow inbound TCP 139, 445 and UDP 137, 138. Use netsh advfirewall firewall add rule if you prefer the CLI.
  3. Check DNS – Run nslookup <printer_name> to confirm the name resolves to an IP. If it does not, add the correct DNS entry or edit the hosts file.
  4. Test Connectivity – Send a test print. If you still see RPC server unavailable, run ping <printer_ip> and telnet <printer_ip> 445 to confirm network reachability.
  5. Verify Driver Compatibility – Install the latest 64‑bit driver from the manufacturer. Avoid a 32‑bit driver on a 64‑bit OS.

Quick Sanity‑Check Checklist

For more detailed guidance on Windows networking, see our Windows Networking Guide. If you need official Microsoft support, visit the Microsoft RPC Server Unavailable article.

Quick‑Check Checklist

  • Create an account – sign up on the Forest VPN website and verify your email.
  • Download the app – grab the Windows/Mac/iOS/Android client straight from the official site.
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  • Test your connection – run the built‑in speed test and double‑check your IP with a public lookup service.
  • Enable kill‑switch – make sure every packet goes through the VPN even if the connection drops.
  • Set up multiple devices – add your phone, tablet, or smart TV to the same account for seamless protection.

FAQ: Your Most Common Questions

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Forest VPN is a privacy‑focused VPN service that encrypts all traffic, blocks ads and trackers, and offers unlimited bandwidth.

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Next Steps: Keep Your Connection Secure

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