Invalid key was pressed
Explanation

The terminal operator has pressed a function
key in response to a screen displayed by the CINT or CINC transaction,
but the function key was not valid for that screen.

System action
The function key is ignored.
User response
Use the correct function key.
Module
CIUA00HC, 
CIUA000C, CIUA100C, CIUA150C,
CIUA200C, CIUA240C, CIUA250C, CIUA260C, CIUA300C,
CIUA400C,
CIUA410C, CIUA420C, CIUA440C, 
CIUA900C
, CIUACM00,
CIUACM10, CIUACM20, CIUACM30, CIUACM40
.
Destination
Terminal end user.