Error: Cannot open file. Add-in not loaded: Solidworks

Hi All,

Last week we updated from Solidworks 2017 SP2 to Solidworks 2018 SP3.

My PC got a clean Windows 10 1803 x64 install, and Solidworks and Solidworks Electrical was installed completely clean.

When I opening a 3D model from Solidworks Electrical, I get this error:

In SW 2017 I also got this error. But with the clean install of the OS and SW, I don't expect this error anymore.

When I click OK, the file will open in Solidworks, so it looks like that there is no problem, but I want to know what the error means, and how I can fix this?

So, is there anyone who can explain this error?

Thanks.

SolidworksElectrical