Selected value of X, then game stopped allowing me to do anything
I was casting March of Otherworldly Light, I selected X=2, I then realized I wanted to tap my mana myself because I wanted to make sure I still had red up to cast Flame-Blessed Bolt, when I clicked my lands nothing happened, so I clicked the select button to cast it (assuming that it would work out). Then the options to cast/change X disappeared but the game didn't seem to think that X had been selected and just pulled up the timer on me and counted down. I couldn't make any game actions but was being penalized for slow play. This was stressful. Then when it ran out nothing happened, the game was just stuck, I couldn't do anything - not even concede. I had to quit the program even though it wasn't frozen (I could still open the bug report button to get here).