if you are brand admin search for this user and transfer his/her surveys to your account.

I don't think that works. I have a similar situation and I need to take ownership of a dashboard that was created by a since-departed user. I have ownership of the surveys that make up the dashboard's data sources, but still cannot access the dashboard. Is there a way to transfer ownership of the dashboard itself?
Thanks,
Tory

Hi torybart
Yep I'm not able to do this either, I can transfer surveys fine but the dashboard I have access do I'm unable to edit and even as the admin I cant give myself the edit rights since I didn't make it....
Hopefully someone out there will know the solution !

Hello rmprest and torybart -
Had the same issue today. Followed the instructions here: https://www.qualtrics.com/support/vocalize/sharing-dashboards/adding-project-administrators-to-a-dashboard-cx/
Because the original owner's user rights were downgraded, you will need to re-enable the account and make it a brand administrator again to access the dashboard. When following step 5 in the Adding & Removing Project Administrators section, be sure to search for yourself by your first name so you get your correct record from the drop down. By habit, I entered my email and couldn't understand why I couldn't add myself as administrator. Hope this works for you.