Sometimes, encrypted archives suffer from bit rot or transfer errors. Standard tools will simply reject the password. Advanced repair tools can sometimes repair the wrapper of the archive so the password decryption engine can function correctly again.
This typically happens when a file download is interrupted. Even if 99% of the file is intact, standard tools will refuse to open it. ArchiveFix utilities can often force the extraction of the partial data that is present, salvaging the majority of your files. archivefix download