the exporters give you a map that you can play in Minecraft. in GrindCraft, you have to build the item that comes right before the exporter. then click the exporter. it will open up a webpage in your browser. wait 5 seconds. on the new web page, click "Skip Ad" button in the top-right corner. it is a yellow button. the minecraft map will download. then, follow the instructions (Method 3 of 3) on this website: http://www.wikihow.com/Download-Minecraft-Maps
There was a bug and it is fixed now! A few days no bonus ticks were given, but now all is back to normal.