We generally recommend disabling the feature "Track Changes" before conversion.
As a result, the conversion runs faster and is also more stable (especially for large documents in which many changes have been made).
How do you proceed?
Go to the Review tab on the ribbon. Click the Accept button and then click Accept All Changes and Stop Tracking.
Save this Word document under a different name and start the conversion (Export PDF button in the axesWord tab).
If you then want to continue working on the document, you can work with the previous version in which the feature "Track Changes" was active.