A few things you can try in Bluestacks:
- log out of your Google account, then back in;
- log out, quit Bluestacks, restart it again, log in to your Google account;
- in Application Manager in Bluestacks, clear the data and cache for the Play Store and Download Manager (or similar according to the emulator). Then restart your device and try to install it again.

Hopefully something here will help fix it.
It would more likely be a Google account/Play store error, not related directly to Bluestacks (but where restarting Bluestacks would be similar to restarting the Android device) as other users encounter this with normal Android devices occasionally, so if these do not work, run a similar search for other solutions.