Changes disappeared

I made some changes to my forms 3 months ago and now when I opened the sheet some of the changes were kept and others not, I get an error when I am opening some sheets and not sure if this has something to do with it.

Sorry for the inconvenience. If you have made modification and this have been lost, you may check the revision history. Here you can see all the modification done in your form and recover or undo any changes made.

In regards to your error, we had an issue in our servers that caused the error. Our team has already resolved the issue and should not cause any problems. Please clear you cache and cookies. This should resolve the error.

Please let us know if you have any other question.