> Source: [sk169555](https://support.checkpoint.com/results/sk/sk169555)

# sk169555 - Endpoint Security Client fails to upgrade with "Error 26760.Can't register catalog file"

| Property | Value |
|----------|-------|
| Solution ID | sk169555 |
| Date Created | 2020-09-22 |
| Last Modified | 2020-09-30 |
| Technical Level | Advanced |
| Products | Endpoint Security |
| Versions | Cloud, E89.X, E88.X |

## Symptoms

- * Endpoint Security Client fails to upgrade with "Error 26760.Can't register catalog file"  
  In installation log:  
  "Check Point Endpoint Security -- Error 26760.Can't register catalog file: C:\\Program Files (x86)\\CheckPoint\\Endpoint Security\\Anti-Malware\\msvcrt.cat"
* Upgrade is successful only when no user is logged on to the machine.

## Cause

Microsoft Sandbox causes the issue.  

This is a default behavior of Microsoft Sandbox that prevents the host OS components from changing while the sandbox is executing. This can hold different catalog files in "open" state under the Hyper-V Child process.  

The Microsoft Sandbox depends on the Hyper-V service, which is why disabling the Hyper-V service helps resolve the issue.  

This behavior is not going to be changed by Microsoft and is present from Windows 10 1903.  

**Note:** When no user is logged on, the catalog file is not occupied by Microsoft Sandbox.

## Solution

This solution requires authentication. Please log in to view the full solution.

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