I have just spent several hours in order to upgrade SourceTree Mercurial, something which should be a trivial process with a teeny bit more help from SourceTree to know where to look.
Every time I started SourceTree recently I got the message telling me that the recommended level of Mercurial was >= 3.7.3, but nowhere in the message did it even give me the basic information that I needed to look in "Tools -> Options -> Mercurial". Adding that in the message would have saved me hours. Adding the link directly to the right Options page would have saved me even another minute looking. Not just detecting that Mercurial is out of date, but offering me a "Update Embedded Mercurial" button there in the message would have saved me even this.
I tried the SourceTree update; said my SourceTree was up to date. I went to the internet and researched Mercurial. I downloaded Mercurial and installed. Restarted SourceTree. Rebooted my machine. Reinstalled Mercurial. Went round and round this loop a few times. Looked on my C: drive. Found I had two versions of Mercurial (one in "Program Files\TortoiseHg" directory, one in "Program Files\Mercurial" directory), but both seemed to be the latest.
I eventually found it in the Options menu, found I was using "Embedded Mercurial" and clicked "Update Embedded Mercurial" and 2 seconds later, the job was done.
It's only because we are IT people using SourceTree that we have learnt to be so determined to find how to fix things.
Please though, use the information that SourceTree knows (e.g. where the exact option panel is) to help us not have to spend so much time looking!
Thank you!