Started a normal queue. When the Match Found! window pops up, once I click on Accept, it starts freaking out and blinking a lot. It also goes back to the accept/decline window, and you can click it again.

I had this happen as well. Gave a message that mentioned a null. However, i made it to champ select.

note: I was in shop when match popped - although that may not matter.

Damn you posted it first xD Same here

Happened to me and a friend, it said two times "Active Game Not Found", then back to queue

Got this too. It seems that people can change their decision to accept or decline while the message is still going, cause i saw 9 people accept and then 2 decline. still, it doesnt seem that accepting once and doing nothing while the new windows appear changes your decision, but you can click the new window buttons.

Same thing pretty much. Clicked accept, started to blink so i pressed accept multiple times. Showed some error where was written [null] and transfered to queue.

Oh good, I don't have to post a new thread about this

Seems to happen in any mode Ive been in.