When I update to joomla 3.9 I have this error I dont make any other thing like upgrade joomla. any ther module works fine, and for the system I cant reinstall payplans. I work in local, I dont up the web an any server. I dont know if this have error in normal server. Anyway if you work in local nos update joomla or get this error, I proof this with many local webs in my computer.