The Kunena team has announce the arrival of Kunena 7.0.8 [K 7.0.8] in stable which is now available for download as a native Joomla extension for J! 5.4.x/6.0.x./6.1.x. This version addresses most of the issues that were discovered in K 6.2 / K 6.3 / K 6.4 and issues discovered during the last development stages of K 7.0
I uninstalled everything from Kunena in System - Manage - Extensions and then reinstalled Kunena 6.2. I then had to install the language file and everything was OK.
No error messages and everything works as it should.
Do you mean uninstall Kunena Dashboard Tools Kunena?
No, because that would remove Kunena completely.
Use the Joomla Installer to uninstall.
Now, I have understood..... I unistalled only the Kunena component with joomla installer, and reinstalled with package I downloaded from kunena.org, without having further error messages.