"Uploading media failed! Please try again later."


The “Uploading media failed” may be caused by some sort of issue at the TCP level. Using WireShark to investigate what is happening, clicking on the “tweet” button seems to open 2 TCP connections (which makes sense, one for the text of the tweet, the other for the image), and both connections seem to fail. The error packets are shown in black in the attached images. This is a permanent condition, and happens with two separate apps: Firefox, and Microsoft Edge. Environment: Windows 10, 64-bit.