This pattern is often caused by corrupted composer data in the workspace database. You can fix it by deleting the workspace storage for that specific workspace.
Open ~/Library/Application Support/Cursor/User/workspaceStorage/
Find the folder that matches your workspace. You can check workspace.json inside each folder
Delete that folder
Reopen the workspace
You will lose chat history for that workspace, but it should open normally again.
If it still crashes after clearing workspace storage, share the logs from step 1 and I will dig deeper.