Today I have been busy away working on some .net extension code. The integration code is fairly simple and does not lead to any kind of complexity that would have manifested in any issues. The code had been working during compiles and applies into my SalesLogix instance. Then all of a sudden it just stopped working. It seemed very odd to me that it would have stopped in such a way and without any kind of indication such as an exception in the .net code itself. Being that this was an isolated environment that I am using for development I tried several different things such as re-registering the removing and re-adding the custom extensions, re-registering the .net extension core assemblies, uninstalling the client and re-installing and the same with the server components. I also tried the code on several different instances of SalesLogix to see if it was isolated to this VM image or it was a different issue. I finally tried to create a simple .net extension stub, install in into my SalesLogix instance and lo and behold it worked. Given this information I went down the path to see what could have gone wrong with the custom extensions that were now working. I noticed that the assembly version for one of the assemblies was 0.0.0.0, which seemed strange to me considering there was an automated build task to handle upping the assembly version. Looking at the assembyinfo.cs file gave me the final pwop moment that I needed. It seems that somehow the assemblyinfo.cs file was empty and that the needed metadata that the .net extension code needed was not compiled in the assembly. I located the previous version of the file in history and after compiling and re-adding into the SalesLogix instance all was well again.
So lesson learned, make sure you have valid assembly info providing the much required metadata.