This message now dispays on front end"Warning: session_start(): Cannot find save handler 'memcached' - session startup failed"
The back end is still accessible.
the only way I can avoid this error is to set the php version to 7.0 - anything above this causes the error message.
The only extensions installed are Hotspots 5.4.8 and Akeeba 6.6.0;
Joomla 3.9.11