Note: while looking at the issue with Thomas Mortagne, we initially thought that the change in datatype for the datetime column was related only to XWiki version and it had been fixed by XWIKI-8286 . However, the fact that I reproduced on XWiki 11.10 with mysql 5.7 contradicts that, we may still see the problem for wikis above 11.5, if the db server (or connector?) that is used is older .