Backup Fails with WMI Errors

Backup Fails with WMI Errors

Category: Acronis Troubleshooting | Windows System Issues
Priority:CRITICAL
Last Updated:November 2025

Problem

Acronis backup operations fail due to Windows Management Instrumentation (WMI) malfunctions. The backup process cannot retrieve critical system information about disks, volumes, and operating system configuration, causing the entire backup to abort.

WMI serves as a core Windows service that provides standardized access to system information. When WMI becomes corrupted or fails, Acronis cannot query essential details needed to create consistent backups, resulting in failures with error code 1012 and "WMI ExecQuery failed" messages.

Symptoms

Common Error Messages

You may encounter one or more of these WMI-related error messages during backup operations:

Error Pattern 1 - ExecQuery Failed:

Error Pattern 2 - Query Failed with Details:

Error Pattern 3 - Repository Corruption:

Backup Behavior

• Backup plans fail immediately or shortly after starting

• Error appears consistently across different backup types (full, incremental, differential)

• Other Windows applications relying on WMI may also malfunction

• System information may be incomplete in Windows Event Viewer or Task Manager

Impact on Operations

• Scheduled backups fail automatically

• Manual backup attempts produce WMI errors

• Device information may not display correctly in Acronis console

• System monitoring and reporting features fail

Solution

Step 1: Confirm WMI Malfunction

Before attempting repairs, verify that WMI is indeed malfunctioning.

Method A: WMI Control Test

1. Press Win + R to open Run dialog

2. Type wmimgmt.msc and press Enter

3. Right-click WMI Control (Local) in the left pane

4. Select Properties

Method B: Computer Management

1. Open Control Panel → Administrative Tools → Computer Management

2. Expand Services and Applications

3. Right-click WMI Control

4. Select Properties

Expected Results: - ✅ WMI Working: "Successfully connected to WMI" message appears - ❌ WMI Broken: "Invalid class", "Access denied", or connection timeout error

Step 2: Enable WMI Event Tracing

Enable detailed WMI logging to diagnose the specific failure:

1. Press Win + R and type eventvwr.msc, press Enter

2. Click View menu → Select Show Analytic and Debug Logs

3. Navigate to: Applications and Service Logs → Microsoft → Windows → WMI-Activity

4. Right-click Trace log → Select Properties

5. Check Enable Logging checkbox

6. Click OK

Reproduce the Issue: 1. Attempt to run a backup that previously failed 2. Return to Event Viewer 3. Review entries in WMI-Activity log 4. Look for error events with detailed failure information

Some events may contain specific resolution instructions based on the error type.

Step 3: Check WMI Repository Consistency

Open an elevated Command Prompt (Run as Administrator):

Possible Results:

Step 4: Repair WMI Repository

⚠️ IMPORTANT WARNING:
Rebuilding the WMI repository may affect third-party applications that store configuration in WMI. Document installed applications and be prepared to reinstall or reconfigure them if necessary.

Create System Restore Point (Recommended):

4a. Stop WMI Service:

4b. Salvage Existing Repository:

This attempts to recover data from the corrupted repository.

4c. Reset Repository:

This rebuilds the repository from scratch using system defaults.

4d. Verify Repository Folder:

Navigate to %windir%\System32\wbem\ and check for the repository folder:

• If the folder exists and is very large (>100MB), consider backing it up, then renaming it:

  cd %windir%\System32\wbem\ rename repository repository.old

4e. Re-enable WMI Service:

4f. Verify Repair:

Should now return: "WMI Repository is consistent"

Step 5: Rebuild WMI Repository Completely (If Step 4 Fails)

If the repository remains inconsistent, perform a complete rebuild:

5a. Stop Dependent Services:

5b. Rename Repository Folder:

5c. Re-register WMI Components:

5d. Start Services:

5e. Verify:

Test by right-clicking WMI Control and selecting Properties.

Step 6: Restart Acronis Services

After WMI repair:

1. Open Services management console (services.msc)

2. Locate these services: Acronis Managed Machine Service Acronis Agent Service Acronis VSS Provider

3. Right-click each service and select Restart

Or use Command Line:

Step 7: Test Backup Operation

1. Open Acronis management console or agent

2. Run a test backup (can be a small file-level backup)

3. Monitor the backup log for any WMI errors

4. Verify backup completes successfully

Prevention

Regular WMI Health Monitoring

Weekly Verification Schedule:

Create a scheduled task to check WMI health:

1. Open Task Scheduler (taskschd.msc)

2. Create a new task: Actions → Create Task

3. Configure to run weekly as SYSTEM account

4. Add action: Run winmgmt /verifyrepository and log results

PowerShell Monitoring Script:

System Maintenance Best Practices

1. Windows Updates:

   • Install all critical and security updates

   • Restart systems after updates to ensure WMI components initialize correctly

   • Review update release notes for WMI-related fixes

2. Antivirus Exclusions: Add these WMI-related paths to antivirus exclusions:

   %windir%\System32\wbem\ %windir%\System32\wbem\repository\ C:\ProgramData\Acronis\

3. Avoid WMI Corruption:

   • Don't use aggressive system "optimization" tools

   • Avoid force-shutting down systems during backups

   • Ensure adequate disk space (10GB+ free on system drive)

   • Don't manually edit WMI repository files

4. Capacity Planning:

   • Monitor WMI repository size (typically 10-50MB)

   • If repository exceeds 100MB, investigate excessive WMI providers

   • Clean up unused WMI classes periodically

Pre-Backup Environment Checks

Before deploying Acronis in production:

• Verify WMI functionality on all target systems

• Test WMI queries manually: wmic os get caption

• Check Event Viewer for existing WMI errors

• Ensure Windows is fully patched

• Verify adequate free disk space

• Document baseline WMI repository size

Proactive Monitoring

Enable WMI Activity Logging Permanently:

On critical systems, keep WMI tracing enabled: 1. Event Viewer → WMI-Activity → Trace 2. Properties → Enable Logging 3. Increase maximum log size to 100MB or more 4. Configure log retention policies

Create Alerts: - Configure Event Viewer subscriptions for WMI errors - Set up SCOM or other monitoring tools to track WMI health - Create alerts for error code 1012 in Acronis logs

Enterprise Deployment Guidelines

For Large Organizations:

1. Baseline Testing:

   • Test Acronis on representative systems from each hardware model

   • Document WMI behavior on different Windows versions

   • Create compatibility matrix for your environment

2. Staged Rollout:

   • Deploy to test group first (5-10% of systems)

   • Monitor for WMI issues over 2-4 weeks

   • Address issues before broader deployment

3. Standard Operating Procedures:

   • Document WMI repair procedures for your helpdesk

   • Create runbooks for common WMI failures

   • Train support staff on WMI troubleshooting

4. Backup Strategy:

   • Don't rely solely on one backup solution

   • Consider hybrid approaches for critical systems

   • Test recovery procedures regularly

Additional Resources

• Microsoft Documentation:

  WMI Troubleshooting

• Microsoft Support:

  How to rebuild the WMI repository

• Acronis Knowledge Base:

  WMI Requirements for Backup Operations

• Related Article:

  Device Not Appearing in Console

Understanding WMI

What is WMI?

Windows Management Instrumentation (WMI) is Microsoft's implementation of Web-Based Enterprise Management (WBEM), an industry standard for accessing management information in enterprise environments.

Key Functions: - Provides standardized access to system information - Enables remote management capabilities - Supports scripting and automation - Powers many Windows administrative tools

How Acronis Uses WMI

Acronis Cyber Protect uses WMI to: - Enumerate disks and volumes: Identify storage devices and partitions - Query OS information: Determine Windows version, architecture, service pack - Monitor services: Check status of backup-related services - Retrieve system state: Gather configuration data for consistent backups - Track changes: Detect system modifications between backups

Common WMI Failure Causes

1. Corrupted Repository: Database corruption from improper shutdowns

2. Insufficient Permissions: WMI service running with incorrect credentials

3. Disk Space: Not enough space for WMI operations

4. Third-Party Conflicts: Poorly written WMI providers from other software

5. Malware Damage: Malicious software corrupting system components

6. Failed Updates: Windows updates that don't complete properly

Troubleshooting Decision Tree

Related Issues

• Device not appearing in backup management console

• Backup agent registration failures

• System information not displaying correctly

• Scheduled backups failing automatically

• Incremental backups reverting to full backups

Keywords

WMI error, ExecQuery failed, error code 1012, WMI repository corrupted, Windows Management Instrumentation, backup fails, WMI repair, repository inconsistent, module 20, winmgmt, backup error 1012

Need Additional Help?

If WMI repair does not resolve backup failures: 1. Collect Windows Event Logs (System and Application) 2. Gather WMI-Activity logs with tracing enabled 3. Export Acronis logs from C:\ProgramData\Acronis\Agent\var\log\ 4. Run msinfo32 and save system information report 5. Contact Acronis Support with all collected diagnostics