Encountered unexpected error at image fields with no preview style

Patch updated with latest code changes.

Still needs tests.

@silvi.addweb please ensure you are fully reading what is required to put these issues into Needs Review before you do. I have spent a lot of time responding to your issues that are in Needs review but are clearly not ready.

Also please make sure to follow the instructions for checking out and pushing branches to gitlab, it looks like you're committing and pushing work on the fork's 8.x-1.x branch.