> Source: [sk180025](https://support.checkpoint.com/results/sk/sk180025)

# sk180025 - "Error 26798 Failed to access cached MSI of previous version" when Endpoint Security Client upgrade or uninstall fails.

| Property | Value |
|----------|-------|
| Solution ID | sk180025 |
| Date Created | 2022-10-18 |
| Last Modified | 2022-10-18 |
| Technical Level | Advanced |
| Products | Endpoint Security |
| Versions | Cloud, E89.X, E88.X |

## Symptoms

- * Endpoint Security client uninstall or upgrade fails with:  
  "Error 26798. Failed to access cached MSI of previous version. Failed to open C:\\WINDOWS\\Installer\\XXXXXXX.msi.  
  Please contact your system administrator."
* Endpoint Security client upgrade fails and is stuck in upgrade loop
* Uninstall/Upgrade log shows:

  ```
  PatchOldInstHelper HandleError:  An installer error occured.
  
  	Failed to access cached MSI of previous version. Failed to open C:\WINDOWS\Installer\XXXXXXX.msi Error=110
  	Source of error:  f:\ckp\src\ep_calib\eXX_XX\eps\calibrary\install.cpp(769)
  	Last Windows error = #0, The operation completed successfully.
  
  Product: Check Point Endpoint Security -- Error 26798.Failed to access cached MSI of previous version. Failed to open C:\WINDOWS\Installer\XXXXXXX.msi Error=110
  ```

## Cause

Windows cache file for the Endpoint Security client installer was removed from the system, which is a probable cause if Windows Disk Cleanup utility was used.

## Solution

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

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