Can't buy any paid apps on Google Play store, shows "An error occurred. Please try again."
In order of least to most destructive.


clear data on market app, reboot
remove your google account, reboot, add it again
clear data from google framework services (this is similar to above, in that it will log you out, but I'm not sure what else this clears), reboot, sign back in.


the 3rd one was what finally fixed it for me and I haven't had the issue again.