After you deleted your workspaces did you go into your ".proi" directory
and delete your "local.ddb" file? This is the file that corrupts your
workspaces if it gets too large. Even when you delete your workspaces,
this file does not decrease in size. After you delete this file, Pro-E
will create a new one when you create your first workspace.
You do not need to import them back in - while in pro-e (linked to your
workspace) open the largest assemblies in your C-drive, and "save". This
will save your work back into the new workspace. Compare the files and
repeat until all files are in the workspace. This approach has less
errors.
Good luck.
Hollie