@Anders Alvsåker - You will need to track down someone on the team where the board resides and ask them to help you. If there was only one admin on that team, they will need to ask the Miro support team for assistance.

If the board was in a Free Plan team, it would be very easy for someone who is still a member of that team to change the board’s Share settings to Anyone with the link → Can view, and then share a link with you, at which point you could open the board, click on the board title, and use the Duplicate action to copy it to another team that you are a member of. Even if the board is in a paid subscription team, anyone on the team may be able to complete the same steps, but only if the board is visible to them, and the various team/board permissions are set in such a state to allow the above steps to be completed.

Thanks for the info @Robert Johnson. I have now contacted the only teamadmin in this team to see if he has any access requests pending in his email. 

I asked another team member to try opening my board, but he also got the no access message.
I know our company have had several full Miro licenses, but I’m not sure if my specific board was part of a Free Plan or not.