It seems like, in your particular case, installing K 2.0.
"something" on J! 1.5.
"something" did not work for you.
Can you tell us more about the "somethings" that you are using? Maybe you have messed up folder and file permissions on your site? Please read
Securing Kunena
and make sure that all your folders are set with the correct permissions. This may explain why the installation of K 2.0.
"something" did not properly install on J! 1.5.
"something" :dry:
K 2.0.4 contains the English language symbolic name translations. See
Where is the language file?
and check to make sure that the files are installed. If the files are not installed, you might extract the files from the installation kit and place them there by hand.
My suggestion is to try to re-install K 2.0.4.
You might also reconsider the value of running your J! 1.5."something" website and migrate it to J! 2.5.11 or J! 3.1.1 and use more up-to-date and progressively maintained Joomla extensions like K 3.0.1 instead.