Update from GitHub
If there is a bug in EWWW IO, the fixes will land on GitHub before they ever make it to a release on wordpress.org. So if you want to get the latest fixes, you can download it from GitHub and install it. But that might be an entirely new process to some, so let's break it down.
First, you have to Deactivate your existing copy of the EWWW Image Optimizer. You can't have two versions active at the same time, or you'll have problems.
Second, you should delete the EWWW Image Optimizer. Technicially, the version from GitHub will live in a different folder, so they COULD co-exist, but that's going to be confusing.
I may have given you a link to the GitHub download, but this link will always point to the latest code: https://github.com/nosilver4u/ewww-image-optimizer/archive/master.zip
Or you can browse over to https://github.com/nosilver4u/ewww-image-optimizer and click the green download button and select Download ZIP.
Note: If you use the cloud edition, it is available at https://github.com/nosilver4u/ewww-image-optimizer-cloud but if it hasn't been updated in a while, feel free to remind me!
Next, we go to Plugins->Add New and then we click the Upload Plugin button at the top of the page.
Then, click on Choose File, and find the file that you just downloaded from GitHub. Click Install Now to upload the ZIP file and unpack it on your site.
When this completes, just one step left, click the Activate Plugin button, and that's it!