Unable to generate New Address

I have an issue with my WordPress plugin, it says cannot generate new address. I have checked all the settings and everything seems to be fine, not sure why I am getting this error.
Any idea on how I can fix this?

Update: I recently got an email saying: Your merchant account is disabled due to low balance.
What does this mean? I thought the balance goes directly to my wallet

You are getting this error because you recharged your credit balance. Head over to Merchants → Payment Fee and add the balance to your account. Once successful the plugin will start working again.
Just make sure to top up your account regularly to make sure this doesn’t happen again.