2.90_SP6.exe - Application Error - The application was unable to start correctly (0xc0000018)

Has anyone else experienced this issue when upgrading to 2.90 SP6? We are getting this error message in the System Event Log when trying to run the 2.90_SP6.exe file on both our Primary and Disaster Recovery Servers.

“2.90_SP6.exe - Application Error - The application was unable to start correctly (0xc0000018)”

We used the same 2.90_SP6.exe file to upgrade 30 Client Workstations without any issues whatsoever. We are running the executable with admin privileges on the Servers and upon running we get to the PatchBootstrapper Window, Click Yes, and then nothing happens. Viewing the System Event Logs shows the Application Error (0xc0000018) populate at the same time we try to install 2.90_SP6.exe. Our servers are currently at Version 2.90 SP5 CU02. Any help would be greatly appreciated.


You may need to open a support case.

Do you know which component it is failing on? If you do, you can find the patch files in the %Temp%\Patchupdate directory (While the dashboard is still open), copy that folder somewhere else and attempt to install them individually, for example using msiexec /p UnifiedServer.msp /L*V C:\Temp\UnifiedServerInstall.log

This will create a verbose log that may show the issue.

I am seeing the same issue with Windows 11 with a Client install using SP6. I think it is a .NET issue but that is my guess. Event Viewer Pictures (imgur)

I had this issue as well. Once I restarted, the SP installed successfully.

I discovered that a reboot of the server didn’t always work. When that occurred, I did a repair of the installation and it resolved my issue.