Re-connection to concrete5.org account required

Permalink
Dear guys,

I am a German writer of books. 3 years ago I had a webdesigner build me an authors website on the basis of concrete5 (v5,5). Now 3 yrs later she has abandoned webdesign and I lost contact with her.
I am now trying to manage the site on my own. Day to day editing is not the problem, but recently I saw, that the tweetcrete addon she built into the site for me does not show my twitterfeed anymore. After unsuccessfully trying to reactivate it, I decided it would probably be best, to reinstall the whole thing.
But when I tried to that, I got the following error message:

"Re-connection Required

This site needs to be reconnected to the concrete5 community. This typically occurs because the site's base URL has changed.

concrete5.org Account

You must enter the username and password of a valid concrete5.org account. This user account must be associated with the project as an owner or developer."

I do have login and pass for day to day editing (posting) of the site, but apparently that is not what is needed now. The error message suggests to me, that there is some sort of master account that my webdesigner maintained at concrete5 platform, that my site needs to be connected to but apparently is not connected to anymore for whatever reason (no, the base url of my site has not changed since it has been set up). As mentioned before she does not respond to my mails anymore, so apparently I have no chance to get the required login from her.

Thus, my question is: Is there any way that I can setup the required account with the concrete5 community and connect my existing website to it?

Thanks in advance and best regards,

Thomas