I love the Rotation Lock functionality which was added a few versions ago of SolidWorks.

It works great if you use the "Show Preview" option in your workflow, when mating components:

However, I'm faster than my computer and I've always hated Show Preview, because I have to wait the 0.5 seconds or whatever after every mate for it to think about it, move the component, and add it.  I can add mates far quicker when I drop in a new component by just roughly positinonig it, doing my 6 or 8 clicks or whatever in 2 seconds to add the 3 mates I need and hit the checkmark, and the component(s) snap beautifully into place.

Unfortunately, the Lock Rotation mates all fail when the Show Preview option is un-checked.

I think what's happening is it's trying to solve the rotation lock right away, first... then trying to position the component in space, but can't, because it's trying to turn it.  The rotation lock should be the very last thing solved in the chain of mates that were added.

Unlocking/relocking the newly added mates on the feature tree does absolve the errors... but it then shows the parts as unconstrained ( - ) and you can spin them.

So this is definitely a bug.