Unfortunately, the error code will be unique to your community so we can't troubleshoot the problem just with what you've provided here. If removing the changes and saving again doesn't fix your layout, you should be able to revert to a previous version of your community using the instructions here. Following that, if you're still having problems implementing the changes you're expecting please raise a support ticket with details of what you're trying to do and we'll help you out. We'll also then be able to interpret any exception IDs you're seeing.
I hope this is of help. Look forward to hearing from you soon.
Regards
Noaman
