Characters change or disappear after editing a markup

This issue occurs when the font being used is corrupted.

Solution

If you do not require the specific font causing the issue, changing the text to a different font will likely resolve the issue. If you do require the font, begin by testing whether the issue is caused by the system font or the embedded font in the PDF.

Set up a test document:

1. Create a blank PDF.
2. Insert a text box and enter text using the same font causing the issue.

If the issue persists, the issue is with the font on your system. If the issue does not persist, the embedded font in the PDF is corrupt and will need to be removed.

To remove an embedded font:

1. Go to Document >Reduce File Size . The Reduce File Size window appears.
2. Under Output Options, click Edit. The Reduce File Size Custom Settings dialog box appears.
3. Go to the Images tab and clear all checkboxes. Then go to the Miscellaneous tab and clear all checkboxes.
4. Go to the Fonts tab and ensure the Drop Embedded box remains checked.
5. Click OK. The dialog box will close, and you will return to the Reduce File Size dialog box.
6. Click Save at the bottom of the window.
7. You will be prompted to overwrite the existing file or save as a new copy.
   1. Click Yes to replace the existing file with your new changes.
   2. Click No to save the PDF as a copy with a new name. It is recommended to save the file as a copy since it allows you to keep the PDF in its original state should you need it.