Thanks for the pointers, I think the issue is more fundamental after I install the module the list gives an error of [UniGrid]Error during reloading data. When I try to add a new record I get
Server Error in '/Kentico11' Application.
[DataClassInfoProvider.GetClassStructureInfoFromDB]: Class information for class 'SensorPro.Configuration' not found.
It seems to work perfectly, if I just leave the provider code in the CMS\App_Code\CMSModules\SensorPro directory. Ehen I delete this and move to my external dll I start getting issues. The dll is installed in the bin directory.