Thanks for contacting our helpdesk.
Have you tried rebooting both the Mako and Openreach modem.
Can you please confirm which site this is?
What troubleshooting have you tried to date?
When did the issue start?
Have you confirm with Marketstall head office that this site has been allowed to connect to the Head Office VPN.
Please send us also a screen shot of the MakoScope (LAN IP) diagnostics page.
Before you do this, can you establish please if you can ping the Mako VPN Concentrator, 10.1.4.1? (Maketstall only!)