Website gets blocked for multiple users

[REDACTED]

Since a few weeks ago we get complaints of users of our web application that they can not load the page. They get a ERR_EMPTY_RESPONSE (324) error. We didn't know what caused it until now. Apparently they use Avast or AVG, and when you load the page with those anti virus software packages the page will be blocked.

What could be the reason for this and how can I solve it? I tried to check several blacklists online but every tool says our site is save and not blacklisted.

There are too many users to tell everyone to just whitelist our site. The strange thing is that it came out of nowhere. We never heard of the error before and all of a sudden multiple users have this problem.

[Eddy]

Tell them to update to the latest version.
If that isn't solving it, have them disable the port scan in the firewall.

Please (re)search before posting.
This (and other things) have been told/explained many times already.

[REDACTED]

Isn't there something else we can do? There are a lot of users who have the problem. There is no way we can let everybody know that they have to update their anti virus. There are a lot of users who have is so letting everyone know they should update is not an option.

[Eddy]

Mention it on the website so everyone can read it.
Please also mention that avast is already working on it and a fix will be released soon.

[REDACTED]

But the problem is that they can't reach the website since the anti virus blocks it.

[Eddy]

Well, if they contact you point them to one of the many threads on this webboard that is explaining it.

Nothing we can do about it.

[REDACTED]

But if we have (for example) 1000 people with this problem only 300 probably will report it. The other 700 will just quit. We cant reach them.

[Eddy]

As I said, nothing we can do about it.

[REDACTED]

But is there a way I can find out why it is blocked so I can do something about it?
Is the IP or domain blacklisted? Is there something wrong with the SSL certificate? I have absolutely no info now.

[Eddy]

Very likely it is the port scan bug as I already mentioned.

[REDACTED]

In my case, I can't reach game called FOOTBALL MANAGEMENT ULTRA in facebook until I disable the firewall. what's the matter ? 

[Eddy]

See reply #1

[REDACTED]

thank you, I'll come back soon 

[Pondus]

Tell them to try this

Turn off port scan

Avast UI -> Protection -> Firewall -> Settings -> Advanced -> Uncheck "Enable automatic port scan detection"

[chris...]

Tell them to try this
.....

Don't think it's so easy for him

But the problem is that they can't reach the website since the anti virus blocks it.

However, it is a bit odd that he really has no way of doing it by any other way