I upgraded Kentico to hotfix version 48 for CMS 8.2. Now I am getting this error
'URLHelper' is an ambiguous reference between 'CMS.Helpers.URLHelper' and 'CMS.GlobalHelper.URLHelper'
This was working perfectly before the upgrade. I get this error after I login from administrator interface.
CMS.GlobalHelper.dll was renamed to CMS.Helpers.dll (both DLL and namespace), so there shouldn't be both available. Check your project folder (Lib and Bin) and if there is a file CMS.GlobalHelper.dll), then delete it. Only CMS.Helpers should stay there.
Also check your project references and review complete content of those folders, you may have somehow corrupted installation. Ideally compare your project file system with a fresh installation.