Blank image/octet stream file error.

Sometimes, when I try to upload an image, I get an error message saying:
 

 
I have no idea what the first error means, since I don’t know what an “application/octet stream file” is, and I’m not sure how the images keep resulting as blank (unless the website can’t process the image for whatever reason? I’m grasping at straws).
 
Does anyone know what the issue is and how/if it can be fixed?
 
If it helps, this only comes up when I try to upload a vector.

It means whatever you uploaded wasn’t recognized as valid / was broken. Where are you uploading from? Do you have an example image?

This vector here on Deviantart was the most recent case.

@FrustrationInExcelsis  
DA stopped allowing vectors some years ago, it’s possible they no longer serve them properly, especially ones from 7 years ago. I’d recommend attempting to save the vector locally and upload from your machine.

All right, thank you for your help.