Sometimes you might face printing issues while working in PDF Expert - there could be several troubleshooting options for each case. 

1.  Follow the steps to fix file-specific issues

1. Launch PDF Expert and open your PDF.
2. Go to the File section.
3. Select Print > Save as PostScript.
4. Open your new file in the Preview app.
5. Select Print.
6. Select Export as PDF.

2. Try printing the file in the Preview app

If you're using a printer with system drivers and if you have trouble printing a file - e.g. some of the elements are printed in black, something is absent on the page or the file can't be printed at all, the reason might be related to the system. PDF Expert uses the macOS system printing, thus we're always suggesting that you try printing the same file in the Preview app since this app uses the same system component as ours in terms of printing. 

• If the file can't be printed or prints erratically from the Preview app as well, the problem is most likely on the system's side, and we hope this might be fixed with a macOS update. However, you can contact Apple Support just to make sure that your vote for this fix is registered.
• If the file can't be printed in PDF Expert, but prints just fine in the Preview app, please contact us at rdsupport@readdle.com and we will be happy to help you personally. We would also appreciate it if you could send us the affected file - if it's too large to be sent over email, you can upload it to any cloud storage service and share a link with us - you can also use a third-party service like WeTransfer.