when i want to upload a track it says: Your account must be connected/linked with your ManiaPlanet account.
but when i click connect now(mp4 account) it says An error occured! no state found!
what can I do?

That's strange. I just unlinked my account and linked it again and it's working normally.

I suppose there could have been some issue with ManiaPlanet when you reported it an hour ago.

When you click to connect it, does it take you to the ManiaPlanet.com website?

it looks like this for me: https://imgur.com/RGbHGYn (still does)

it now worked when i tried with different browser

I'm glad you got it to work !

eyebo.wp says:
(...) I just unlinked my account and linked it again and it's working normally. (...)

Hello, I'm trying to unlink my MX account from the MP one, in order to link it to a new one. Is this possible? If so, how? I have accessed my profile page, but it just says:

https://accounts.mania-exchange.com/user/profile/336 says:
Your account is currently associated with: matto

... with no option to unlink it, apparently.

I'm sorry to bring back up such an old topic, but I used the search function and this seems to be a very close match.

Hey matto,

I've manually unlinked your account. You got to log out and log in again using your MX credentials and then you should be able to link a new MP account to MX.

Ozon says:
Hey matto,

I've manually unlinked your account. You got to log out and log in again using your MX credentials and then you should be able to link a new MP account to MX.

Thanks Ozon, it worked like a charm. Although it is kinda strange that you have to do so manually each time.

It is on purpose to avoid users changing their account links to bypass some restrictions made to avoid spamming and voting fraud.