AviUTL freezes the first frames of the video


Momo's Minion
Everything is in the title, whenever I try importing a video to add a cover, the 100 first frames get frozen and I can't find how to fix that (re-importing the video fixes it at the first playback, then the problem reappears). I can't seem to find anything about that on the English web
Got it from here (found it on a random Korean site, has some stuff the main English download doesn't have)
Not sure it helps but specs are an i5-6500 8gb ram and gtx 750