Bug with auto start workflows

​There appears to be a little bug in workflows that has crept into SharePoint since December 2011 CU.  If you have an auto start workflow and the library has require check out set to yes, then the workflow will not start and will be stuck in starting.  You can avoid it by setting require check out to No.  Microsoft are aware of the bug and “may” include it in June 2013 CU.  In the mean time you can install April 2013 CU and request the hotfix from MS, currently there is no KB number to reference you just explain the problem and they’ll FTP the hotfix to you.  Of course you should try this on a test environment first.