Hello Mike,
Thank you for posting your query on Microsoft Community Forum.
I would appreciate if you can provide us the following information to help us understand the issue better.
Which app you are referring to when you say “I have an app that says the operations is too large for the undo buffer”?
Just for more clarification we need the screen shot of the app which you are using to buffer.
You can refer to the link provided below to add screen shot in your post.
How to include a screenshot in your post
Hope this would help. If issue still persists post back with current status of your computer and result of proposed suggestion, we will be happy to assist you.
Thank you.