Hello and welcome to WeMod!
The issue you are having with the loading screen could be caused by WeMod already running in the background.
Launch Task Manager
(i) Either CTRL, Alt + Delete then select “Task Manager”.
(i) Or Right-click the taskbar and select “Task Manager”.
At the bottom of the Task Manager window make sure the “More Details” view is selected.
Scroll down to “Background Processes” and look for all instances of WeMod.
Right-click all WeMod appearances and choose “End Task” on all of them.
Once all WeMod processes in Task Manager have been closed, try launching it again.
I had this issue earlier myself and the above resolved it for me.
Otherwise, double-check that WeMod is added as an exception in your AntiVirus, even if you’re sure it already is (try disabling antivirus entirely to see if this changes anything at all). And if you have the fusspot known as Comcast, double-check that the advanced security feature is disabled, since it likes to block legit software such as WeMod.