Apply Configuration fails

After 2 years running the fPBx with all the configuration setup and working for a year. Then, after upgrading to 2.9.0.5 We’re unable to ‘Apply Configuration Changes’ Not sure where to start looking for solution. Any suggestions are appreciated.

Cheers,

This has happened to me in the past I had to run

/var/lib/asterisk/bin/retrieve_conf
&
/var/lib/asterisk/bin/module_admin reload