Upgraded to Vesion 9.0

I have upgraded to Version 9.0 (yours 9.0.0.4865 Release 2014-11-10

And now I get the following on all the databases I try to connect to:

“Connection using old(pre-4.1.1) authentication protocol refused (client optin “secure_auth’ enabled)

Same problem for me.

Should be great to have a checkbox in advanced tab to disable "secure_auth".

Yes. Same problem here too!

See the release thread.

And see the v9.1 release, which fixes this problem.

http://www.heidisql.com/forum.php?t=16895