Core issue
The error message can look similar to this:
%C4K_SWITCHINGENGINEMAN-3-TXCNTMEMORYPARITY: Parity mismatch in transmit count memory, addr=E18D, reg bits=8000E18D, total=1
There is a soft parity error in packet memory, and it can be transient or a hardware issue.
Resolution
If the error persists, use the TAC Service Request Tool in order to open a service request with the Cisco Technical Support.