How to access/disable "basic" firewall

[the.tick]

I recently, inadvertently, clicked thru some links and it installed avast.

Now my friends cannot connect to my minecraft server. Previously they had no problem.

I just had a avast popup talking about a basic firewall. When I click on the avast icon on the toolbar, I see no way to access rules for that firewall, nor to I see any setting to disable it.

How can I open my minecraft server for my friends?

[DavidR]

A screenshot of the popup/notifications would be helpful. 

Avast Free (if that is what you installed ?) doesn't have a basic firewall.  I suspect that you are seeing a notification that you only have a basic firewall (the windows one), effectively a promotion to but Avast Premium Security that does have a more comprehensive firewall.

These promotions/ads for other avast paid products is the cost of having avast free (as I do).  I don't like them as I don't like the methods employed to push them, but I just ignore them.

So if you have avast free, these popups are unrelated to blocking friends using your minecraft server, so again a screenshot of any error screen, etc. would be helpful.

[the.tick]

Yes, it's the avast free version. You are most likely correct in that the popup was a nag for the paid version of avast.

What I do not understand is why my friends cannot connect to my minecraft server. The ports are forwarded correctly and it used to work. The only thing that changed on this PC recently is avast being installed.

[DavidR]

Unless you can get information on why they can't connect, e.g. any error messages they are getting (it's hard to say) ?

What firewall are you using ?
What antivirus did you have before Avast and how did you remove it ?

Assuming that you have your minecraft server setup (I'm no gamer so I have no practical experience of doing this), then I would assume that Avast would be able to scan the traffic content.  If avast isn't alerting (?) I guess that is one positive.

I don't know if this will help found on a search:
https://gaming.stackexchange.com/questions/350959/why-can-t-other-people-join-my-minecraft-server