Thanks to help from freepbxhosting.com the issue is resolved.
First problem (deleting extensions) was done using mysql commands in previous post. You would need to replace ‘1’ with the extension you are trying to delete. The following resource guided this:
Second problem, the reason why GUI was not available was that I had the WAN IP for my local networkl banned by fail2ban which scans logs for certain security related errors and bans an IP which caused it.
The following resource helped identify the root cause of the ban and to unban my ip:
[1] https://www.freepbxhosting.com/how-to-help-ive-been-blocked-from-my-pbx/
The root cause was that I had some setup a softphone (Voiper) with incorrect configuration.
To fix the problem I had to:
- Delete the bad account config on the softphone so it does not keep causing the problem
- grep for the incorrect configuration in config files with /etc/asterisk folder and then manually edit them to fix or remove bad configuration.
I then repeated the steps to unban in [1] and after that I am back to normal.