The error message indicates that there's a problem with the header of the database file, and a character in the bigram is outside the expected range of 0, 32-127.
The solution for me after some research was to go to the directory of the update db
Rebuild the locate database: The locate command relies on a database of files in your system. If this database becomes corrupt, you can rebuild it. On a Mac, you can do this by running the following command in your terminal:
cd /usr/libexec/
and then run
sudo /usr/libexec/locate.updatedb
Which rebuilt my locate database
NOTE that this can take a while and there isn't any progress bar so make sure to just wait till the command exists I think thats what was happening to me when I tried to update the db the first time I exited too early