The tag is present in Lintian version 2.104.234. That is the most recent version we know about.
The file name in the native source tree is not valid UTF-8. File names must decode as valid UTF-8. Please rename the file.
Unlike other file names in Lintian, which are printed in UTF-8, the attached reference shows the bytes used by the file system. Unprintable characters may have been replaced.
Refer to Debian Policy Manual section 10.10 for details.