I have a very small c# dll which is working on my localhost, a test server, and 1 of our 2 production servers. It is failing on our second production server. It is unable to load the dll or one of its components. The dll has been loaded into inetpub\wwwroot\appeon\AEM\components on all 3 servers. The testing application has been deployed via the same configuration to all 3 servers.
I also have another c# dll, used by another app, which is working correctly on all servers. Both dlls are created with MS Visual Studio 2017. Both dlls are created with or for the 4.51 version of dotNet. Both are created for any cpu type.
Neither dll has been registered.
The error message has been attached.
I need ideas for what is different, or how to find it.