Black boxes appearing in Premiere and program lag?

[Rayane5C27]

When I open any file in Premiere, it keeps loading with these blacked out windows and heavy lag, I can still change settings so ran through some trouble shooting tips in the preferences but that's not helped.

My version is up to date and so is my PC, my file doesn't have any dynamic links that would be causing the lag, when I check my task manager it says that its using 4000mb of memory (not sure if thats related).

Im trying to create my final project for college, is there anything I can do to fix this?

[Ann Bens · Accepted solution]

Try resetting workspace

and/or

FAQ: How to reset (trash) preferences.

and/or

FAQ: Deleting Media Cache files