Security error message when posting pics?

I'm trying to post a series of photos and I keep getting a message that says 'security error, hit the back button and try again'. What gives?

 

I would get that message when I tried to send pictures from my scanner. When I cropped the images smaller, it would work. Have no idea why, but if it works,it works.

Sent from my SM-T350 using The H.A.M.B. mobile app

 

Yeah, I think your images are too big(too many Kilobytes or Megabytes). Try resizing and then upload.

 

Maybe you are actually not logged in anymore, refresh the screen and if you see Sign In at the top corner you've be Logged out try logging in again But Wait...Select All the post and copy so if it is so when you log in you don't lose your well thought out post...trust me it happens...

File Type perhaps incompatible format and as alluded Huge Filesize can all be culprits...