craftconomy3 Version: 3.3
vault Version: 1.5.6
for some reason when ever a non OP player tried to type anything to do with craftconomy it gives them a "permission denied" error.

you need to set up permissions for the various commands. I use permissionsEx to handle plugin permissions, and this is the part i set up in that plugin for craftconomy3:
groups:
default:
options:
default: true
permissions:
- craftconomy.money.balance
- craftconomy.money.pay
- craftconomy.money.top
- craftconomy.bank.create
- craftconomy.bank.balance
- craftconomy.bank.deposit
- craftconomy.bank.withdraw
- craftconomy.bank.list

thanks