thanks for the feedback. as per File TV PHP warnings from Smarty templates, PHP 8.0 · Issue #15792 · modxcms/revolution · GitHub suggestion i set “debug” to “0” in modx2.8.4 settings and that disables the reporting and the manage error-log does not fill up with those error entries. there is an underlying issue there but i can’t fix it 
and i see no fix on the modx support pages or google, and i am using the very latest modx2.8.4 now, so i’ll just hide it for now .