My device is Motorola Xoom MZ604. The internet connectivity is 4G WiMax via my laptop as hotspot. The problem is when I'm trying to download any app from Google Play Store, it gives me an Error 504 with the message I mentioned in title.
However, if I navigate to the application via browser and click:
Install → Select Device → Install and then restart my device, it sometimes works.
Some googling brought me that it's a gateway timeout error. But I'm still unable to figure out how to work around the problem. So looking forward for your help.