I upgraded to 2.1.0.1 from 2.0.3.1 yesterday.
I am getting the same message reported earlier in this forum by many users...
Also the solution mentioned have also been chaecked and is found to be ok ...... but in I have a classic case to report...
In my case API user is not getting added.... I tried n no of times.... the aded user is getting lost ..... where i dont know.... you the oopencart ppl should know....
i want solution urgently.... unable to process the orders....
otherwise i will have to revert back to old version.... i have a backup.... but not sure whether the oders placed after shifting to 2.1.0.1 will be available or will be lost....

?
I am in big trouble because of this faulty upgrade....
I have seen the support from opencart is also not coming quickly....
else will have to move to prestashop... or something like that where support is available quickly...