Adobe Acrobat/Reader is the default software used by QuickBooks to print transactions. Unable to print selected checks is one of the possible effects of an outdated version. You can update it so you'll be able to print your checks and other transactions.
If the web page indicates that a newer version is available, choose Install Now.
Click the downloaded file and follow the instructions.
Once done, log back in to your QuickBooks Online account and print your checks again.
If updating your Adobe Reader to the latest version hasn’t fixed the problem, you can repair your Adobe installation. For the detailed steps, kindly refer to this article: How to update, repair, or re-install Adobe Reader/Acrobat. It also contains information on how to uninstall and reinstall Adobe Reader.
To view how much you're paying each vendor on a monthly basis, you can run a monthly expense report by vendor. For the detailed steps, you can check out this article: How to run a monthly expense report by vendor. It also contains information on how to save the report for future use.
Please let me know if you have other concerns. I'm just around to help.