Well, if you've deleted both .inis below, both scripts should open at the default position
C:\Users\YOURUSERNAME\AppData\Local\Autodesk\3dsMax\2016 - 64bit\ENU\en-US\plugcfg\CoronaConverter.ini
C:\Users\YOURUSERNAME\AppData\Local\Autodesk\3dsMax\2016 - 64bit\ENU\en-US\plugcfg\CoronaProxyExporter.ini
If that doesn't help and you still cannot run the scripts (either via drag and drop or the "Run Script..." command) then your max is probably somehow blocking script execution and that's unrelated to Corona or these 2 scripts =/ . I don't think only reinstalling corona will help, it may be better to make a fresh install of max.
I think reinstalling will not invalidate your trial (but I'm not entirely sure). If reinstalling screws up your trial period please open a ticket and make a reference to this thread, tell them it's my fault ;) .