What causes passcode format error?

[AustinYockel]

I have a user who fails to connect two or three times before it lets him through.  In the logs I see "Authentication method failed, passcode format error."

I'm assuming the only thing that changes between the times he succeeds and the times he fails is the generated passcode.

What could be causing this?

[NathanFurze]

From knowledge article - https://knowledge.rsasecurity.com/scolcms/knowledge.aspx#a58074

Symptom

Authentication method failed Passcode format error

Passcode format error received in Authentication Manager 7.1 real time activity monitor.

A 7.1 passcode format error is the same as a 6.1 or earlier Syntax Error

Cause

The number of characters received by Authentication Manager during Authentication was not equal to the min/max number of characters expected based on the Passcode Definition.  If this happens for a few users, they are probably typing wrong, maybe forgetting to enter their PIN.  If every user from a RADIUS Client gets this error, then the RADIUS secrets are not the same on the Client and Server, so decryption is always wrong and adds too many digits to Passcode.  In rare case the Node Secrets could be mismatched, but that usually results in Node Verification error.