BarTender prints 2-3 Labels and then stops, displaying either Error 3700 or Error 3721 (LX Series Printers).
A Windows Automatic Update has caused a problem in the BarTender software which produces this problem.
Check out this article on BarTender's knowledgebase for the latest information and solutions:
https://support.seagullscientific.com/hc/en-us/articles/225047808