Drupal 8 - PDF tax receipts not working after upgrade from 1.5.1 to 1.5.2

PDF tax receipt generation was working before the upgrade but not after. During the upgrade I also replace the logo and signature images but that is probably not related.

Trying to print a single tax receipt causes the modal window to freeze.

The url ending /civicrm/cdntaxreceipts/view produces a blank page.

Log output from the upgrade looks good:

406	Nov 10 15:02:05	[warning] Deprecated function CRM_Core_DAO::executeQuery, use calling functions should handle exceptions.
399	Nov 10 15:01:51	[warning] Deprecated function CRM_Core_DAO::executeQuery, use calling functions should handle exceptions.
392	Nov 10 14:59:47	[warning] Deprecated function CRM_Core_DAO::executeQuery, use calling functions should handle exceptions.
390	Nov 10 14:47:40	[info] Running task: Finish Upgrade DB to 5.30.1
388	Nov 10 14:47:40	[info] Running task: Upgrade DB to 5.30.1
386	Nov 10 14:47:40	[info] Running task: Begin Upgrade to 5.30.1
384	Nov 10 14:47:39	[info] Running task: Finish Upgrade DB to 5.30.0
382	Nov 10 14:47:39	[info] Running task: Upgrade DB to 5.30.0
380	Nov 10 14:47:39	[info] Running task: Begin Upgrade to 5.30.0
378	Nov 10 14:47:38	[info] Running task: Finish Upgrade DB to 5.30.beta1
376	Nov 10 14:47:38	[info] Running task: Upgrade DB to 5.30.beta1
374	Nov 10 14:47:37	[info] Running task: Begin Upgrade to 5.30.beta1
372	Nov 10 14:47:37	[info] Running task: Finish Upgrade DB to 5.30.alpha1
370	Nov 10 14:47:36	[info] Running task: Add core (required) extension Financial ACLs
368	Nov 10 14:47:36	[info] Running task: Upgrade DB to 5.30.alpha1: SQL
366	Nov 10 14:47:36	[info] Running task: Upgrade DB to 5.30.alpha1
364	Nov 10 14:47:36	[info] Running task: Begin Upgrade to 5.30.alpha1
362	Nov 10 14:47:35	[info] Running task: Checking extensions
360	Nov 10 14:47:35	[info] Running task: Cleanup old files

How do I get error messages from this module?