Try this without a Wacom and check.
Using the Apple mouse - nothing works in Develop module. Sliders for exposure etc do not respond and the crop tool is totally non-functional. Tried with graphics processor enabled and disabled - makes no difference.
I still have LR 5.7 on my machine and everything works fine in that. This would suggest a bug in LR rather than the Wacom driver.
Any other suggestions?
Seems to be a permission issue.
Can you try another admin user account and then try.
Yes, tried that. Permissions seem to be fine. If LR 5.7 works fine I don't see how it can be a permissions issue.
Sent you a private message.