Check printing requires a valid vendor/grantee record for the payee. In many areas of FIMS when making idcode changes, importing or manually adding records you will be unable to save the record until either a vendor record is created for the payee or the payee id is changed to an idcode with a vendor record.
There are still a few situations where it is possible to save a record with a payee id that does not have a vendor/grantee record. When the check printing program encounters one of these vouchers, it will skip over it if in a batch or display a message if there are no vouchers selected after the others are skipped.
If you open the Open Items tab to the browser view ( click the binocular icon at the top or click F3), when on the Default View, you will see two columns. One column is for Vendor Id and another is for Payee Id. If the two idcodes are different, it would be a good idea to check the Payee ids if these are new, not recalled vouchers. If you do feel like vouchers are being skipped for payment, then start with these vouchers. Changing the Payee id to a valid vendor id or adding the vendor record for the payee idcode will resolve the issue.
Frequently the problem will identify a voucher that is actually attempting to pay the wrong payee idcode.