Inserting image causes app to crash and get 404 error

[PRIMETSS]

I need to look into this more, so just posting as a to-do.
But today, while editing a blog post and adding images on about 5 occasions (did resize most, but not all) after hitting save I got a 404 and seems site crashed in Azure and automatically restarted...

[CeriQ]

This could be related to an issue I encountered with certain images breaking the regex that picks the image data from the post content.

[CeriQ]

It appears that XmlDocument does not support escape characters other than &, < and >, except for the ones using hex codes. If you try to add a file using a non ASCII character, the character gets replaced by the browser and the load of the xml fails in BlogController line 127.