I am getting the same blank "Plugin" screen issue when installing "JSON 1.1.6" to EE 2.7.3. I tried setting $debug 1 in the admin.php and don't get any trace either.
Oddly enough, the JSON plugin installed just fine on my "dev" instance. It's my "production" instance crashing. Best I can tell, the paths and options are exactly the same in both instances.
Any help appreciated. It's important that I get this working soon.