Recent updates to the "Android System WebView" and/or Chrome may result in the inability to print SMS conversations to .PDF from SMS Backup & Restore. This seems to have started with the update on Oct 6, 2020 (version 86.0.4240.75). This is not an issue with just SMS Backup & Restore, it also affects other apps that use the WebView to print, for example the GMail app also fails to print emails to PDF.

Update: New versions of both "Android System WebView" and Chrome are now rolling out on Play Store.
If you have a device running Android 10 or later, make sure you have the "Android System WebView" updated to version 86.0.4240.99.
If you have a device running older version of Android, make sure you have Chrome updated to version 86.0.4240.99.

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For devices running Android 10 or later:

As a temporary workaround to enable printing to PDF, the update to Android System WebView app can be uninstalled.

To temporarily downgrade Android System WebView:

  1. Open Play Store on the phone
  2. Select "My apps & games" from the menu on the top left
  3. Scroll down to "Recently updated" section
  4. Tap on "Android System WebView" in the list
  5. Tap on the "Uninstall" button and confirm that you want to uninstall

If the "Android System WebView" does not appear in the "Recently updated" section in the Play Store, you can get to it directly by tapping on this link.

After that you can go back to SMS Backup & Restore and print the conversations. Once you've finished printing, you can reinstall updates from the Play Store again.

For devices running Android 8 or 9:
As a temporary workaround to enable printing to PDF, the update to Chrome app can be uninstalled.

To temporarily downgrade Chrome:

  1. Open Play Store on the phone
  2. Select "My apps & games" from the menu on the top left
  3. Scroll down to "Recently updated" section
  4. Tap on "Chrome" in the list
  5. Tap on the "Uninstall" button and confirm that you want to uninstall

After that you can go back to SMS Backup & Restore and print the conversations. Once you've finished printing, you can reinstall updates from the Play Store again.

NOTE: Remember to reinstall the update from the Play Store to receive the latest security and bug fixes.