Error when creating Customers after upgrade from 6.5 Update 6 to 6.6 Patch 7723

Error when creating Customers after upgrade from 6.5 Update 6 to 6.6 Patch 7723

Version:

6.6 Patch 7723

Issue:

The Cashier was getting errors while creating the customer at POS.
In the second attempt, the same customer was created successfully.
Then tried to create another customer which again failed. After that, we suggested trying to create a customer at the Management console, which also failed and some time error was also changing.
Few times it was an Overflow error message and sometimes an Incorrect syntax error.

Resolution:

It was observed that restarting the POS and MC resolved the issue successfully and the customer could be created successfully after that.