Why did I just lose 3 hours worth of work???

After a certain point in my form, it failed to save my progress... I went through it a second time because it seemed to be frozen. I copied what I had done, going through very slowly and saving after every step/every new thing I added.  I made sure it was saving it.  

I continued on to add more to my form (about another hour to do), then tried to make a change, and all of a sudden all of my progress was gone.

Apologies for the inconvenience.

If the changes were saved in our server and you were able to see them in your previewed form, then you can check your form's revision history by following this guide: https://www.jotform.com/help/294-How-to-view-form-revision-history. That should let you revert back to the version of the form where all the changes were made.

It's possible that you might have been logged out or your session has expired while making changes on the form, which resulted to this problem. 

Please also make sure that you have not opened the form builder on multiple tabs on the same browser, if you are opening multiple tabs and editing multiple forms or have the form builder opened multiple times, that would also caused problems.

Let us know if you were able to revert back to the original one.