Web page error-cannot be reached

When I login and then click on Optimize, I get the following error:

This site can’t be reached

The webpage at https://www.askmrrobot.com/optimizer might be temporarily down or it may have moved permanently to a new web address.

ERR_SPDY_PROTOCOL_ERROR

What web browser are you using? Are you accessing the site on mobile?

This support post on google might help you out – this appears to be an issue with Chrome for some people.

https://support.google.com/chrome/forum/AAAAP1KN0B0sfAqeo4hDy8/?hl=en&gpf=%23!topic%2Fchrome%2FsfAqeo4hDy8

I get the same “site cannot be reached” message when I try to follow you google forum link! LMAO.

Chrome and Edge. Situation is the same on both. Neither on mobile.

Here’s the part of the post that may be of interest:

Ok, I’ve figured out a permanent fix. It turns out it actually is Avast, Chrome and Avast don’t play nice with each other for whatever reason. To fix this issue permanently, you have to go Into Avast ==> Settings (Gear icon) ==> Active Protection ==> Web Shield (Customize Button) ==> DESELECT “Enable HTTPS Scanning”. Then click OK to all the menus and flush your sockets again. It’s been a week or so since I did this and I haven’t got the error since (with heavy browsing of the sites that most commonly threw the error before). Obviously the downside is Avast no longer scans HTTPS websites but I’d much rather have usability than that feature, at least until the problem is fixed. What’s weird is disabling Web Shield or Avast entirely never did the trick for me, only turning off this one specific option worked. Hope this helps you guys. Maybe we can now go bother Avast to fix the issue.

And the flushing sockets thing he is talking about is in chrome:

The only fix I have found is to go to chrome://net-internals/#sockets and click “Flush Socket Pools” which does do the trick and everything works fine afterwards, however it is only temporary and the error starts to appear again after a little bit of time.