BIGIP throws syntax error for iRule upon upgrading f5 to 12.x for below : set given_context_path [string trimright [URI::path [HTTP::uri] 1 1] "/"]

BIGIP throws syntax error for iRule upon upgrading f5 to 12.x for below :   set given_context_path [string trimright [URI::path [HTTP::uri] 1 1] "/"]   The below warnings logged in BIGIP seem...