Since ITSM 7.6.04 until 9.0.00, on every Remedy service startup, we have an error displaying on arerror.log
390600 : Could not find or read the optional license tags file. (ARNOTE 452)
/Path/to/your/ arsystem.tag file
There is already a workaround published on KA361327 and a product defect for this error but, since this error and defect is more than 4 years old now, it would be great that BMC definitively fix this error by creating this arsystem.tag directly with the installers.