TestLink

When I change the language to any language except 'en_GB' via "My Settings" page, I get following warning:

string 'bug_link_tl_to_bts' is not localized for locale 'en_US'
or
string 'bug_link_tl_to_bts' is not localized for locale 'de_DE'

Is there any other configuration that I need to do for using different language?

Yes, the strings are primarily created in the en_GB area.

So, copy the same variable and string found in locale/en_GB/strings.txt file, to the same area in the
locale/en_US/strings.txt file. The string variables start with $TLS, so the one you have above would be found in the file like this: It might be easier to do a diff of the two strings.txt files to see what else might possibly be needed.

Thank you for the help.