Error while opening files

I have developed an add-in in visual studio. It is running smoothly for an year now.

But from last two weeks I am facing an issue while opening files (especially drawings and assemblies) in SolidWorks when it is launched through visual studio (while debugging).

Please note that this error doesn't occur when i open SolidWorks normally, even though add-in is loaded.

Thanks in advance....

SolidworksApi/macros