I have an Umbraco site that used grid layout, and I wanted to delete an unused row configuration that hasn't been used (didn't even have any valid content types defined).

After I deleted it, the grid layout is now missing completely, replaced by a default setup with just two basic column definitions. I can't see any of the previously defined content as Angular just throws the error "Cannot read property 'columns' of undefined". Any ideas as to how I can undo or fix the issue?