Some letters are missing on the print out and are replaced by squares. This issue first came up with Adobe Reader but could also affect other software.
The print job contains fonts that are referenced as lower case and upper case e.g. “Arial” and “arial” and as the TPWinPrn is case sensitive it tries to embed both but can only find one of them on the system. That’s why some letters are included and the others are not because embedding those letters failed.
Apply the new TPWinPrn print processor.