I guess this has been discussed before in here: https://answers.atlassian.com/questions/156779/difference-in-diif-suppression-between-windows-and-mac-sourcetree
Hopefully it helps!
I'm on a Mac and file up to 1Mb work fine. I don't know if the 1.8Mb is the reason for the message - diff suppressed (file size or pattern) or is it "pattern". I don't know what "pattern" means. The file compares OK when using the "External Diff" button which starts FileMerge on my MacBook Pro (OSX 10.8.3)
Supported Platforms macOS Windows We recently introduced support for additional hosting services such as GitHub Enterprise, GitLab (Cloud, Community Edition, Enterprise Edition), and...
Connect with like-minded Atlassian users at free events near you!Find an event
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no Community Events near you at the moment.Host an event
You're one step closer to meeting fellow Atlassian users at your local event. Learn more about Community Events