Error Description:

The error, "Invalid class" appears when trying to login and register EasyWorship.

Resolution:

Left-click on the Windows Logo Start button on your taskbar at the bottom of your screen.
Click in the search bar or you may first have to click on the little magnifying glass to get the search bar to appear.
In the search bar, type in the word "update", without the quotation marks.
At the top of the search results, click on Check for updates.
When the Windows Update window comes up, click on Check for updates.
If there are any pending Windows updates, please update them and then restart your computer.
When your computer is up, try logging in to EasyWorship again.
If you are still receiving the Invalid Class error, close out of EasyWorship.
Click on the attached Invalid Class Error Fix batch file that is located at the bottom of this article to download it.
If you get a pop-up in your browser that that says the Invalid Class Error Fix.bat isn't commonly downloaded, and it wants you to trust the file. You need to click on the three little dots icon on the right.
In the drop-down, click on Keep.
On the next screen, click on Show more.
Then click on Keep Anyway. (Now the file should download.)
Once the download is complete, click on Open File.
If you get this screen saying that Windows protected your PC, click on More Info.
Click Run anyway at the bottom.
Click Yes to Allow the app to make changes to your device.
Click OK on the DllRegisterServer in cimwin32.dll succeeded box.
After the batch file is done running, the window will close.
Restart your computer.
When the computer is back up, open EasyWorship and try logging in again, and the error message should no longer appear.