SourceTree not showing the diff just says 'select a file to view the diff'

[Phill Ashworth]

When I select a modified file the diff isn't shown in the adjacent pane, it just says "select a file to view the diff" even though I have selected a file. Some files correctly show the diff but others don't.
I'm on the latest 3.4.10 version.
Any ideas how to fix this?

[Philippe Cloutier]

Good question. My colleague and I are evaluating Sourcetree 3.4.12 and both of our installs are affected. Sourcetree is at its defaults, using the embedded Mercurial 4.8.1, which surprisingly appears to be the latest one available. Trying to use a system Mercurial seems to fail, although there is no error.

We first thought all files were affected, but my colleague noticed the side diff works for .hgtags.

[Philippe Cloutier]

This is a 3.4.10 regression. My colleague and I both went to 3.4.9 and that fixed it for us.

[joedf]

Downgrading from 3.4.14 to 3.4.9 worked for me. Thanks!

Git diffs worked fine, but not Mercurial diffs...

[David Spitzley]

It appears that this is still a bug.  I just downgraded from the most recent version back to 3.4.9 and it works again.

[David Spitzley]

That's interesting:  II absent-mindedly installed v3.4.18 on a new server using Mercurial, and the diffs don't show up for .php files, but it turns out that .env and composer.lock files (I'm using Laravel, FWIW) display diffs just fine.  So apparently the file type is involved in this problem. 

[MrJJ]

I also suffer from this "feature" and so far found no fix.  I also installed it on another laptop and the diff is not working there either.   both win 10.  so maybe it's my repro.