Unknown error: Solved by clear cache in AOT

I have found many strange cases from AX2012, R3.
There are errors from some seessions user. But another users did not face error in same time.
Surprisely, the error can not solve by clear user seesion cache.
It need to clear cache in AOT.

1. Error-After press contact in PO.

2. Error-When post customer invoice.
Cannot generate correct voucher number.
(This case is customize program for generate voucher number by monthly)
By the way, this case i might solve by clear cache in number sequence manually.

2.1 Error number sequence exceed but master setting is correct, not exceed.

2.2 Error number sequence continuous but I tried to solve by checked and unchecked, result was not OK  .