@Traxo: Thanks. So it's a database issue. However, there is few information in these posts.
It seems it is also not included in the official "issues" list.Offering a working client which is compatible with the network would involve way less difficulties the only "problem" would be to spread the word about the new client and get users and, more importantly, exchanges to run it. But that's nothing unsolvable, imho.
It would be interesting to know if the bugfix requires a consensus change (hard or soft fork). If it's only a database issue it doesn't look like that, so it should not be too difficult to convince nodes in exchanges and other services to run it. If the owner of the website refuses to include the "Community Edition" in the download section on his website, a simple Github Pages website could be created to present a trustable source for the Community Edition.
I'm not really a developer and much less a database specialist, I'm interested in Qora mainly because of its smart contract platform (shared with Burst), but as the coin seems to be in a crisis, I'm spreading some ideas here ...