Segmenting Existing Contacts

Your software
My Mautic version is: 4.3.1
My PHP version is:
My Database type and version is:

Your problem
My problem is: How do I go about segmenting my exisiting contacts that I imported to my Mautic instance?

These errors are showing in the log:

Steps I have tried to fix the problem:

When you do an import you have the option to either tag all the imported contacts or assign them to a segment as part of the import process.

If you have already imported and you don’t want to repeat the process then look for some common data point and use that as a filter to create a segment or apply a tag.