SPS local user login error SyntaxError: Unexpected token (4383797)

If a user attempts to use a federated login (SAML) which fails during initiation then tries a Local user login attempt, the following error appears: 

SyntaxError: Unexpected token '<', "<!--C"... is not valid JSON 

After a failed federated browser login initiation, the next local browser login can inherit a stale cached data

STATUS:

Change Request # 722986 will address this issue in a future release of SPS, subject to successful QA and Product Management approval.

WORKAROUND:

Press F5 to refresh the browser then the local user login is successful