Thank you for the post @TimBennett
Yes, without commit, your changes will not be applied. It looks like the error you are getting is caused by corrupted Threat database. There are several KB articles addressing this issue:
If you have access to support portal: https://support.paloaltonetworks.com/ then I would download latest package from: Updates > Dynamic Updates, then upload it to your Firewall and install it, then try commit again.
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