Theme hanging after plugin installation

Hello

First i wanna thank you for the Theme, Arcade Basic is pretty nice. I think about buying the pro theme. But i have some troubles with the theme right now. Last time if i install some different Plugins it’s always the same problem, after activating the plugin is working correct, but the theme Dashboard is hanging. I can’t load the Media, can’t put new widget in sidebar, cant put new menupoint, it don’t stop loading. I checkt another theme with the same plugins and there is it working. I just have that problem with arcade. I don’t know what i can do… Maybe you can help me? I really like this theme and i wan’t change to another theme, but now i can’t work this way.
Thanks & best regards Tobi