Re: Firefox cannot display certain images and shows "This image <image> cannot be displayed because it contains errors."
"This image <image> cannot be displayed because it contains errors." is a place holder message that gets replaced by the image when Firefox is ready to render this.
Can you post a link to a publicly accessible page that doesn't require authentication (signing on)?
Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).
Do NOT click the Reset button on the Safe Mode start window or otherwise make changes.
You can inspect and manage the permissions for all domains on the about:permissions page or for the current domain via the "Site Identity Button" (globe/padlock on location bar) and click "More Information" to open "Page Info" and go to the Permissions tab.