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Veeam Agent backup job fails with "Failed to call RPC function 'TestCompatible': Error code: 0x80070008. Cannot initialize COM runtime" error

Veeam Agent backup job fails with "Failed to call RPC function 'TestCompatible': Error code: 0x80070008. Cannot initialize COM runtime" error

KB ID:	3077
Product:	Veeam Agent for Microsoft Windows
Published:	2019-12-26
Last Modified:	2025-02-19
Languages:	JP

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Challenge

A Veeam Agent backup job managed by the backup server fails with the following error:

Processing Error: Failed to call RPC function 'TestCompatible': Error code: 0x80070008. Cannot initialize COM runtime.

Cause

When a backup job starts, Veeam Backup & Replication connects to the Veeam Agent machine to initiate the backup process. The connection is based on Windows API and uses RPC and WMI queries. If Microsoft Windows is low on desktop heap memory for services running under LocalSystem account, Microsoft Windows can reject the incoming queries. As a result, the following message will be displayed in System Event Log (eventvwr.msc) of the Veeam Agent machine:

Log Name:      System
Source:        Win32k
Event ID:      243
Task Category: None
Level:         Warning
Keywords:      Classic
User:          N/A
Computer:     
Description:
A desktop heap allocation failed.

DCOM errors (Event ID 10010) can be found in System Event Log of the Veeam Agent machine too.

Solution

Article Applicability

This article is relevant to a specific scenario where the Windows OS suffers from a 'heap allocation' failure.

The solution provided in this article should only be performed if Event ID# 243 is found in the Windows System Event Logs (eventvwr.msc).

To resolve this issue, update the registry key to increase the desktop heap memory size. Mind that this change affects the desktop heap of all services, so do not make the value larger than necessary. To update the registry key, do as follows:

Run regedit.exe.
Navigate to the HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\SubSystems key.
Locate the Windows string.

Edit the third "SharedSection" value in the Value data field as shown below:

Before

After

Click OK.
Reboot the Veeam Agent machine.

More Information

A previous version of this KB article documented the use of a tool to identify the process responsible for a memory leak, which may have been causing the heap memory issue. However, beginning with Server 2012 R2, Microsoft changed the core logic of the heap memory management system, rendering those publicly available tools incompatible. If you come across the Veeam error mentioned in this KB and find Event ID# 243 in the event viewer, we recommend opening a case with Microsoft support to seek assistance in locating any service memory leaks.

If this KB article did not resolve your issue or you need further assistance with Veeam software, please create a Veeam Support Case.

To submit feedback regarding this article, please click this link: Send Article Feedback
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Veeam Agent backup job fails with "Failed to call RPC function 'TestCompatible': Error code: 0x80070008. Cannot initialize COM runtime" error

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