Weird thing I have noticed in the system with this kind of error... I installed the system starting with version 4.3.2 and then upgraded it to version 4.6.1. I really don't know the right steps on how to Upgrade the system??? Maybe you can share to me the right steps to upgrade. Should I follow the proper sequence of versions to upgrade or is it OK to skip some version and proceed to the latest one? With this kind of error, I have noticed in some modules of the system also appear this kind of error. What I did was to copy back some modules of 4.3.2 (only those that have error) to the current version and the error is gone. So now, my current system version 4.6.1 is mixed with 4.3.2. The warehouse.php file is 4.3.2 because if I put the 4.6.1 then the system won't open.
What should be done first or the steps to upgrade? Please advice! Thank you very much