updates to open door theme

Hi. I dont know where else to ask this - I bought Open Door realestate theme in December 2015, and its worked just fine. My support has expired, and now I need to upgrade to php 7.2 and Im getting some fatal errors in the theme. If I pay for extended support, is there an upgrade to the theme which can help me, or is it time to find a new theme?
Many thanks

The theme hasnt been updated in 3-4 years so I would be surprised if it still works with WP5 or newer PHP versions

You could always hire a freelancer to check it but it is very difficult to determine what would be involved exactly without investing in investigation

Many thanks