Yonke imikhiqizo Isithangami Sokwesekwa

I keep getting an error message (see uploaded image) that says Thunderbird can't update to the latest version and to download it manually. When I look at the About for Thunderbird, it says it already is the latest version (see uploaded image). So, I ignored that error message the first few times, but when it kept appearing, I downloaded and installed the update (after backing up the Profile folder in case of mishap; see uploaded image). It said it was installing and then the Install box disappeared (it did NOT say "You already have this version" and stop installing); I assumed it had finished (although, it never asked me to do anything, even though the error message implied I'd need help, and I couldn't see any difference in Thunderbird after it finished). Today, I got the error message AGAIN (even though I updated yesterday). What does it want me to do? Is it updated, or not? I'm confused.