I have been trying to download level up for the past week and I keep getting this same screen in the Extension manager. See where the blue bar is? That is where it get's stuck and stays! I just want to play, but can't figure out how to get it to download without getting stuck here every time. Any suggestions?
Apologies for the experience! It looks as if the problem is not specific to the "LevelUp for Photoshop" extension, but has something to do with Extension Manager. I can see from the screenshot you have 17 updates pending to Adobe products. Would you consider updating, and then trying to install the extension ?