2212805 - Firefighter login returns an error "Name or password is incorrect (repeat logon)" and throws a dump CONVT_NO_NUMBER

While logging in with a Firefighter ID, it returns with an error message "Name or password is incorrect (repeat logon)" and throws the following dump in the backend:

Category                         ABAP Programming Error
Runtime Errors               CONVT_NO_NUMBER
Except.                           CX_SY_CONVERSION_NO_NUMBER
ABAP Program               SAPLSUSO
Application Component  BC-SEC-USR-ADM

Short Text
     "7    " cannot be interpreted as a number

SAP GRC Access Control 12.0

Firefighter, CONVT_NO_NUMBER, Logon, Name or password is incorrect (repeat logon) , KBA , troubleshooting , best practice , plugin , GRC-SAC-EAM , Emergency Access Management , Problem