> Source: [sk171033](https://support.checkpoint.com/results/sk/sk171033)

# sk171033 - Endpoint Security Client fail to upgrade with Error 26760 when Windows Defender Application Guard is installed

| Property | Value |
|----------|-------|
| Solution ID | sk171033 |
| Date Created | 2020-12-16 |
| Last Modified | 2021-02-01 |
| Technical Level | General |
| Products | Endpoint Security |
| Versions | Cloud, E89.X, E88.X |

## Symptoms

- Endpoint Security Client fails during upgrade with the following error:  
"Error 26760.Can't register catalog file: C:\\Program Files (x86)\\CheckPoint\\Endpoint Security\\Anti-Malware\\msvcrt.cat"

## Cause

Microsoft Windows Defender Application Guard \\ Hyper-V services installed on the affected machines.

<br />

## Solution

This problem was fixed. The fix is included in:

* [Enterprise Endpoint Security E84.40 Windows Clients](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk171419)

Check Point recommends to always [upgrade to the most recent version](https://supportcenter.checkpoint.com/supportcenter/portal?eventSubmit_doGoviewsolutiondetails=&solutionid=sk117536).

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