Could not load file or assembly 'System, Version=

Add-in Express™ Support Service
That's what is more important than anything else

Could not load file or assembly 'System, Version=
Error in AddinModule.resx 
Mike VE

Posts: 154
Joined: 2007-09-09
I have a couple of addin's that are distributed with .NET 3.5. However, in order to be able to debug I do development work in .NET 4.51.

On one the machine I use to test deployment I keep getting the error "Could not load file or assembly 'System, Version=, Culture=neutral, PublicKeyToken=b77a5c561934e089' or one of its dependencies. The system cannot find the file specified."

I have scrutinised the project and the setup project and the references are to 3.5 ( throughout. The only place where there is Version = is in the AddinModule.resx file. Could this be left over from me switching from dev configuration (.NET 4.51) to deployment (.NET 3.5)?

How can I solve it?
Posted 09 Apr, 2019 09:45:15 Top
Andrei Smolin

Add-in Express team

Posts: 17184
Joined: 2006-05-11
Hello Mike,

I don't think so. Check all suggestions at

Regards from Belarus (GMT+3),

Andrei Smolin
Add-in Express Team Leader
Posted 10 Apr, 2019 04:51:55 Top