Hey Kevin! I'm not 100% on that exact error, but it sounds like you have that field blocked from updates (overwrites).
Try going to Admin > Field Management > Select & drag in the Company Name field in question on the right-hand side > Field Actions > Block Field Updates
And see if there's a checkmark next to Trusted and/or Untrusted List Imports. If there is, try unchecking "Trusted" and reupload the list as a "Trusted" list import and see if that works.
Hope that helps!
1 of 1 people found this helpful
I have no block field updates on Company name.
This is from Andy Varshneya last year:
The error is occurring due to a system updated Marketo made in the June release. This upload error happens only when uploading a list where the person exists as a contact in the database already. Hopefully Marketo fixes this ASAP, but a workaround for this problem is to save the error log file, delete the Company Name and Import Error Reason columns, and then upload the error log file.
The import process will match by email address and those people will be added to the list.