Hi Andrew,
I see you are getting the error,
TypeError: Cannot read property "urlChecks" from null. (file Code.gs, line 300)
Looking at the logs, it appears that the script is reaching the 30 minute limit, and then throwing the above error:
8/8/2022 1:18:04 AM Resuming work from a previous execution.
8/8/2022 1:48:19 AM TypeError: Cannot read property "urlChecks" from null. (file Code.gs, line 300)
Can you please try increasing the TIMEOUT_BUFFER variable in the CONFIG object (you can try a value of 1000)? It will take more runs for the link checker to complete, but it should resolve the error.