Return code 0 when trying to save data.
run select base_id, * from TableOfContentThatWontSave where status = 1
In my case this was in the ecommerce products module. I needed to find the products that had a status of 1. Each one was listed as blocked. I checked the item under more actions in the top menu, I published the items. Once all items identified by the querry were published and unblocked I was again able to save.
Another possible reason
using the Telerik.Sitefinity.Web.UI.Fields.ImageField, Telerik.Sitefinity with out actually adding an image will cause the same issue??
Actually found the issue today. the update procedure seems to dynamically create itself based on the string passed in and it was 261 char and the field in the database was 255. Updated the field size in sql and it saved no problem.
The dynamic content module table will do the same. identify the item that is in edit mode. go to the item, open and save. This was the first thing I tried. In some cases this is all that is needed.