I placed all my leaders (mleaders were used) and text, then I had to change my viewport rotation 180 deg. Now all my text is upside down. I change my UCS to view and new mleaders and text (which I don't need, I've already labeled everything) come in at the correct orientation, but all my original labels are rotated. How can I make these labels update? I'd really like to avoid having to relabel everything.
I've had this issue and what I had to do was select all the old multileaders and entered a rotation in the properties tab, under Text. That will rotate the text and leader landing, but you will have to move them all by hand if they overlap anything. Select them all at once to avoid entereing the rotation for each one individually.
These aren't C3D objects, just ACAD objects, so they are not as smart.