🇷🇴Romania @ita08

I've also had this problem. What worked for me was choosing to not optimize the CSS for the pdf. I've applied a patch from this issue: https://www.drupal.org/project/entity_print/issues/2971822 🐛 Allow users to choose whether to optimize css. RTBC . Maybe this will help someone.

From what I've understood, a solution might be reverting this line

if ($entity_type->hasHandlerClass('views_data') && $entity_type->entityClassImplements(FieldableEntityInterface::class)) {

back to

if ($entity_type->hasHandlerClass('views_data')) {

Is this the right approach?

Working on it during Drupal Dev Days Vienna, checking it.

Same fatal error also.