I have LR 6.0 in a standalone version for Windows. No issues for a long time.
Today I tried to fire up Lightroom and it won't start.
A window "Lightroom Catalog - Adobe Photoshop Lightroom (not responding)" opens, with a superimposed splash screen.
Windows Task Manager shows LR as properly loaded, consuming 128 MB of memory.
Event Viewer reports no application error.
I have updated Windows 10, to no avail.
The first step is that you have to update your Lightroom to the newest version.
If it's not solved the issue it could be a problem with the GPU support.
Just trying the update.
The Update did the trick.
No issue with the GPU - I have an extra GPU (nvidia) and it is perfectly compatible with the app.