The Image uploader/linker in the Post Editor across all SE sites appears to be stuck.
Cancel and add another image
Your image is too large to upload (over 2 MiB)
As stated, I'm unable to insert an image to this post, but here is a screenshot uploaded directly to Imgur: http://imgur.com/a/WsJeK
I have not initiated the image upload AFAIK, and none of the three "Cancel" buttons nor the Close button does anything. Yes, there is three Cancel buttons and it seems to be trying to both Link and Upload images at the same time.
I have tried to logout/login.