Errors after upgrading from PS 1.7.6.5 to 1.7.7.x

[Kriter.io]

Hello Everybody, I hope you can help me. I run prestashop for several years but i never had the following problem.

After updated PS version from 1.7.6.5 to 1.7.7.0 (and the same errors did not get solved even updating it to 1.7.7.1 and to 1.7.7.2), when i surf my BackEnd and i click, on the left column, on CUSTOMERS i get the list of my customers, then if i click on the name of one customer, i get the following message 

....so i turn on the debug mode and i do the same....and i get the errors showed in the files called CUSTOMERS1 and CUSTOMERS2

...then i noticed it happen the same if i click even on ORDERS and i get the following message:

What do you think it happened?....how could i fix it?

Thanks in advance for your help and support

Regards

Fabrizio