What does the message "SMAUTHREASON parameter value is non-numeric" mean?

When I run Web Agent with login.fcc, I get the following message in the Web Agent log.

What does it mean ?

   [11/08/2016][11:39:07][11:39:07.511][13238494][24159]
    [0000000000000000000000000a099daf-ca00de-5821ffab-5e5f-c75c1053][SmFcc::setup]
    [Warning. SMAUTHREASON parameter value is non-numeric]

   Web Agent checks the SMAUTHREASON during both the GET and POST requests and if it is found to be non-numeric, then SMAUTHREASON is reset to 0
   and a warning message is logged in the Web Agent traces indicating that the value of SMAUTHREASON is non-numeric.