I tryed to migrate my project from Unity 2019.1.1f1 to 2019.4 and faced problem with HingeJoint2D limits and angle. It looks like in 2019.1 the reference angle was equal to the angle between connected rigidbodies at startup while in 2019.4 the reference angle is always zero. I haven’t found any documentation on the value of referenceAngle. Is there a way to force referenceAngle to be equal to the angle at startup in 2019.4.
I’ve previously run into this issue too - it’s a real annoyance. I ended up using custom scripts to calculate my own reference angles and respective logic, but I don’t believe it’s possible to set referenceAngle directly. For your reference though, I had a poke around in Unity 2020.3 today and noticed that referenceAngle does seem to have a value. Not sure when this was fixed, but it seems to work.