I just installed a new version of Umbraco 14.1.1 because the one in was using to develop with gave exceptions when running, making it really slow. Now again on a new installation I'm still getting the same:

Exception thrown: 'System.OperationCanceledException' in System.Private.CoreLib.dll

Could not load file or assembly 'Umbraco.Web.BackOffice, Culture=neutral, PublicKeyToken=null'. The system cannot find the file specified

. Anyone else that has this problem?

Are you building Umbraco from source or from a nuget install ?

The referenced assembly is not part of Umbraco 14. Do you have any custom code targeting earlier versions?

Thanks @nathanwoulfe It was indeed a version problem. I've downgraded everything to 14.0.0 to check and now it works fine. @Kaspar Boel Kjeldsen It was from a NuGet install. Thanks for your help!