Mac Mini won't join wifi network

[vandrv]

I just updated my late 2012 Mini to High Sierra and it has developed a problem. I'm not sure if it is related to the update or not but I doubt it. It worked fine for several days after the update. Anyway today it won't let me join my wifi network. It asks for the password and tells me the password is wrong. I know I am typing in the correct password as everything else connects to it. I reset the modem and rebooted the Mac and the modem several times but it still won't let me join. I have two networks available and it joins the other one just fine. Any ideas as to what my problem might be and how to correct it? Thanks for any help.

 

[imaccooper]

You did not mention trying this and I find this is one of the more common reasons for this problem, go to your saved networks and “forget” the specific network. Once it’s gone, try to reconnect.

 

[vandrv]

You did not mention trying this and I find this is one of the more common reasons for this problem, go to your saved networks and “forget” the specific network. Once it’s gone, try to reconnect.

I did try that and it didn’t make a difference. The odd thing is that I’m having the same problem with my smart tv, but my iPad, iPhone and windows computer log in with no problem. I even noticed on my iPad that it asked to share the password with the Mac and it still said it was an invalid password

 

[Neodym]

I observed the same behaviour, when I tried to connect to a network that has time limits for operation and my attempt to connect was outside the defined times. Maybe you have operation limits based on MAC address?

 

[ActionableMango]

Do you have a very long or complicated password? In the past I've had wifi passwords that were too long and complicated work on some devices (yet others would work fine). Simplifying/shortening the password then enabled all devices to connect.

For example, I used to use a randomly generated 63-character password that looked something like this:

#P^):}_0N6-rX&9L5>f^_mJVv{<W_iZUMEH*:Un__?#L{!E%TgE4D,SZ\&tsqp_​

But some devices can't seem to handle that. Cutting it down to about 1/3 the length enabled all the devices to work.

 

[Pecktime]

I had the same problem. Try resetting your PRAM. There’s a couple of firmware thingys that can become corrupted. PRAM and one other I can’t remember.