Pictures turn green!

The Lightroom default of ProPhoto for external editing in Photoshop is an extremely unfortunate one, to the point where I'm not sure they really thought about the consequences. This thread is a case in point.

The people who need to rely on safe defaults are, of course, the beginners. They should be able to just open the application and start using it, without immediately running into stop-in-their-tracks issues they cannot possibly understand.

ProPhoto is for advanced users who understand the implications, not beginners. These advanced users will be perfectly able to set up ProPhoto on their own. They don't need the hand-holding of application defaults.

The default in ACR is sRGB. It should be sRGB in Lightroom too - and anyone reading this without understanding what I'm talking about, should immediately go into Lr Preferences > External Editing, and change the color space dropdown from ProPhoto to sRGB. No need to ask or hesitate. Just do it.

This sounds like a color management issue.  I suggest confirming that your images are in the sRGB color space prior to uploading to anything on the internet such as social media.

The attached screen capture shows my primary setup and my additional external editor Lightroom preferences.  If you primarily use images for web use you might consider setting up your primary as sRGB

That's a ProPhoto image viewed without full color management.

Convert to sRGB before posting.

The problem with Lightroom, for a beginner, is that it sends ProPhoto to Photoshop by default. You should change this in Lightroom preferences, at least until you get more experience.

Wow. My first thought is color management. What color space, bit depth, and mode are they set to? Are they 8-bit RGB and sRGB?