Hi @Tutku Yilmaz! Thanks for reporting the issue, let’s get down to the bottom of this together!
If you are indeed the board owner, then you cannot restrict your own access to the board.
My guess is that you have 2 Miro profiles. You own the board as profile A but you’re trying to access it while logged in to profile B. As profile B you request access. You open the inbox associated with profile A and click Give access, but in Miro you’re still logged in as profile B, so there’s an error.
If that’s the case, can you please log in under your other email address to Miro and change the sharing settings of the board as the rightful owner so that your other profile has the necessary access? You can also reassign ownership of the board to your other email as described in this article.
If this is not the case, please let me know - we’ll continue the investigation! ️♀️