There was an error while reading a stream - SQL Report Builder

Hi, I use a third party app that creates site reports. The back end is based on MS SQL 2008 and the report is designed using MS Report Builder 2.

I'm now looking to add images to the reports. These show fine in report builder but when exported as PDFs I get occasional issues.

Using the latest version of Acrobat Reader DC (18.011.20035) I get "There was an error while reading a stream" for some images which do not display. I have also tried rolling back to an old version of Acrobat Reader XI (11.0.08) and get "An internal error occurred" and no images are displayed. My OS is W10 64-bit.

To add to the confusion the PDFs are viewable in other programs such as MS Edge, Chrome, MS Word etc.

I have a sample I can send. Any pointers? Thanks in advance.