Toon Boom slow and crashing

Everything was fine yesterday, but now I’m having problems moving files from library onto timeline and vice versa. It takes a long time and occasionally TB crashes.
There’s nothing running in the background on my PC, nothing else is slow. Internet fine.
TB runs fine during playback or when I am drawing, copying, pasting etc. It just takes forever to add anything from the library to the timeline or anything new that I have created doesn’t want to move to the library without a very long wait or TB shutting itself down. Saving my scene takes a very long time too.

Where is the project file and library located? On local hard drive or via network or USB/external hard drive?
It is nothing to do with internet but if any of project files or library located other than local hard drive, it is possible.