Apperently Mojang is blocking specfic ip ranges. For me 132.xxx.xxx.xxx and 134.xxx.xxx.xxx do not work at all. I am lucky to have two providers and could simply swap to the other one which provides me with an iprange 62.xxx.xxx.xxx which works fine for me.
So the problem actually can't be fixed by us since mojang is causing it. The big question now is, why does mojang block those ip ranges.
I just tried usb thering with my smartphone using mobile data. That seems to work for me aswell. So maybe it's really just our networks which cause the error.
So with every IP adress that doesn't start with 102, your were able to connect on servers without getting the invalid token error?
Also, it would be interesting to know If you only use ipv4 or ipv6 aswell. Could your friend repeat this test using ipv6?
So the 24 hour mark from my last logout on my server passed and i am still not able to join any server again. So that what i wrote earlier might be wrong.
Bump.
Still need help, please.
So, quick update from me.
After 24 hours from my last login on that server, i think some kind of reset kicked in and i was able to play again May 24th. However today May 25th i get exactly the same error as the two days before. The question is, why does that keep happening? I am pretty sure that i will be able to play again tomorrow, but the after i am probably not. I just don't understand what is wrong to cause this kind of error again and again.
If someone experienced this in the past and found a fix for this, i'd be super thankful if you could help me.
Mod edit: March -> May
I added two textfiles. Maybe they can help.
As far as i understand what i read there is that my account is still somehow occupied by someone which makes no sense to me.
I also did a test a few minutes ago where i used one of my friends accounts to login, to test if it maybe is my computer or my connection. And it turns out that i also couldn't access the server with the account of my friend, even tho he can still join without any problem. So it might be something wrong with my connection or my computer, which causes the error.
No i don't share my account with anyone. As far as i know at least. And with my few passwort changes, nobody should be able to be still logged in with my account.
Thanks for reopening
I actually have to agree on some points Dominik mentioned. I can understand that the developers don't work on weekend, but this bug came up on wednesday and they could've atleast give some kind of explanation to it, since it was super frustrating looking up this issue. But what pisses me of the most is the error we get. Only a small percentage of the players have some network knowledge and the error we get is completely useless and actually wrong. So how is the majority of the players going to fix this, if the error doesn't provide an actual solution and Mojang keeps saying "we don't know what causes the error".
It took us 4 days to find some kind of solution and now Mojang twitters that they are investigating this. And who knows how long it will take for them to fix that. That's simply not what you'd expect from a big company owned by microsoft.
After this little rent the only thing i'd like to say before i will leave this thread is thank you @Faraaz Sulaiman since you were the one coming up with a first solution for this.