Sudden error message whilst editing

Hello, I am experiencing some cubase problems for the first time in ages. When Im editing or working on the proect page, I sometime get this “A SERIOUS PROBLEM HAS OCCURED, PLEASE SAVE THE PROJECT UNDER A DIFFERENT NAME AND RESTART THE PROGRAMME” or something very similar to those lines.

What could be the cause? I cant figure out but its not a memory thing as it can happen whilst cutting or moving a single track.

Many thanks!