If you have a plugin like buddypress and several add-ons installed, you should always disable the add-ons 1st and the main plugin after.
Here the problem was: buddypress groups extras that was still active with buddypress already inactive and was throwing this error:
[17-Apr-2017 19:38:01 UTC] PHP Fatal error: Call to undefined function bp_is_group() in /home/ohso/public_html/wp-content/plugins/buddypress-groups-extras/bpge.php on line 266
I’ve moved it out momentarily from the plugins folder to deactivate it and now it works, please disable all other plugins and continue the test. (you’ll need to move it back in to reactivate it, but I would avoid that plugin if I were in you, it doesn’t seem to be properly coded)
Thanks
p.s. yes you do have access to your error log it is in /public_html/error_log