Avast creating 504 errors on legitimate websites

I have been a huge fan and promoter of Avast from years, recommending the product to hundreds of users. Recently my wife had to log onto a state website and was greeted with a 504 access denied error. After calling and finding out there was not a problem with the site, it wasn’t until a lot of trial that when I disabled all Avast shields that my wife could log on. I thought this was isolated until it happened again last night on a different website she uses for work. What’s going on with Avast… and why is this happening? I’m a tech and I don’t want to keep loading this on other’s computers if this is going to cause a problem for them to access websites. BTW… the “verification” letters truly suck… try making them readable for people.

Hello,
what are the websites? Are they using http or https? If https then is the certificate self signed?

Milos

One of the sights is: https://www.dora.state.co.us/pls/cproweb/CPRO.Logon

You can’t get to this login page until Avast’s shields are disabled. She has logged on using this same link many times before. I’m sorry, but I can’t sent the URL of the other because you have to be logged on first to get to it and it’s my wife’s work.

Thanks! Mark

Does disabling https scanning make a difference?

Yes, that worked! I’ve been using Avast since 2007 and never had to do that before. Thank you for your help.

https scanning is newly implemented in version 2015 and is not working flawlessly on all https websites at the moment,
or so it seems.