Some time ago I have faced very annoying error while developing custom list definitions in sandbox solutions. Every time when I tried to save a file to a library based on my list definition I received an “410 The web page no longer exists” error. Google did not help me(there are some examples of fixes for similar problem, but all of them are talking about Farm solutions), so I tried to fix it on my own.
After spending some time looking at the schema.xml, I found a solution. Everything You have to do is to remove the view responsible for rendering the “Save As” dialog content. After making the modification in schema.xml and redeploying the solution, the “Save As” dialog started to work. (continue reading…)