Does anyone encounter the problem that the capcha for ryushare is basically impossible to see for humans? Are there any ways to fix this problem?

Me, too.
Why should I do? I also want this answer.

Sorry for the very late reply. They always gave me "You have reached the download limit" error message, I had to test the plugin using several proxies.

From what I know, ryushare's and vidxden's (solvemedia) captcha images are sometimes rather hard to read, but that is also the case when I tested it via browser. While rapidgator that also uses solvemedia captcha is easier to read, and safelinking is the easiest one.

Please compare the captcha via browser. If you find that the browser's captcha image is easier to read, then please post the captcha images comparison.

Ok, now I can reproduce the captcha issue. Please update your solvemediacaptcha plugin (v1.0.6).