Please provide more details. Are you using Windows or Mac? CS6 or CC? I suspect what you mean is actually Exchange Panel instead of Extension Manager. Did PS crash no matter you clicked which extension or only when you clicked a specific extension? Did you see any message box when PS crashed?
I have windows 7, photoshop cc. I believe it has to do with the 64 bit and 32.bit. When I tried to install an app on 32bit if I clicked on any of the button in the Exchange panel it would crash and give me the error photoshop has stopped working, close program. It finally worked but I had to do it in 32bit mode.Thank you for your reply.