When I go to Prefixes I get the following error message. Just found that I get it in IP Addresses too, the rest of IPAM seems okay.
<class 'django.template.exceptions.TemplateDoesNotExist'>
utilities/templatetags/tag.html
Python version: 3.8.10
NetBox version: 3.1.3
I poked through the install folder and found /opt/netbox/netbox/utilities/templatetags. If the error means that it can't find tag.html in that folder then I agree that it isn't there. I upgraded yesterday and haven't moved anything so no idea why it would be missing.