I was asked to migrate a site collection that included a web template for creating subsites to a new site collection. To do so, I downloaded the .wsp solutions from the old collection and uploaded them to the new collection. After some tweaking I was able to get a new subsite created from the web template. I have made edits to that subsite and now want to save it as a new template, but I am getting an "unexpected error" when I try to do so.
The ULS error log shows that an exception is happening "trying to get context compatibility level: System.IO.FileNotfoundException". It seems that Sharepoint is making a call to the old url's /_vti_bin/cellstorage.svc/cellstorageservice
Why is Sharepoint trying to POST to that URL and what can I do about it? Is this just an artifact or am I resigned to recreating the entire template to get this working correctly?