nosilver4u on "[Plugin: EWWW Image Optimizer] Image optimization always show in progress and cannot be optimized"

Yeah, we've had something strange on a few sites with the 2.9.x release. First make sure you're on 2.9.1.
Then, I need to know if you have the Import Tweets as Posts plugin active on your site.
If not, we're looking for a new culprit, and these are the steps to find it:
1. Disabled everything except EWWW, and switch to the twenty sixteen theme.
2. Upload a few images, if it works, proceed, if not, crap...
3. Reactivate a plugin at a time, upload images, see if it breaks, until you find the conflict.