Ok, so for the Mir and Val scene, I selected "Take advantage and take Mir's back". When the scene starts and I choose an action (such as kiss lips, penetrate, or even selecting do nothing) and then click the commit action button, it shows this error message:
Error: <<script>>: bad evaluation: checkedChars.push is not a function.
As for the other bug regarding the join conversation button, I accidentally deleted my save file of it. I'll go back and try to do the same choices I did before to see if I can replicate it to see how I messed it up.