So, someone has inserted images into your file, and you can’t save them out!
Sure, you can go to File – Raster Images, but that doesn’t really help.
The answer is simply to ‘export’ the view to DWG, and Revit will make the images you need.
For a nice, clean, step by step:
1. Make a new drafting view.
2. Select the image / images you want to ‘save out’
3. Copy to Clipboard
4. Paste them into the Drafting View
5. Export to DWG
6. Have a look at the folder that you exported to – there are your images!