There is some limit for cash accounts. Lets go a bit deeper in it to understand why the limit works here in Cash accounts?
The Cash accounts are something that the money operates from the on hand money, which will be paid from what we have in our hands, we cant pay something which is negative limit. So we have an alert to say that the cash in your hand has a limit and you can't proceed without sufficient balance in your hand to make some payments.
There are possible solutions for this situation
1. Transfer some money from other Account to this Cash account inorder to perform the Cash payments.
2. Do the payment from other account which has the Sufficient balance in it.
3. Deposit some money to the Cash account from Miscellaneous or from Customer or from a respective person and than proceed this payment.
Seems like this is not an issue, we can load the cash to the account and make payment to it. Let's take a look at each Steps a bit elaborated.
Transfer Money From Other Account
This is easier and best way to load the cash From Bank or Other Cash Accounts to Current Cash Account. Simply goto Banking->New -> Transfer. Here Choose the From Bank Account and To Bank account and fill up the transfer details and Submit it. Than the balance loaded to this cash Account and you can make payment to any expense from it.
Other Cash or Bank account
If you wish to do it straight away, Simply choose the Alternative Cash account or Bank account and make payment to complete it.
Deposit Money
The Alternative Way is to load the Cash on that account from Direct Deposit Banking ->New -> Deposit and fill up the necessary fields, such as date, amount, from type and exchange rate if other currency account and finish it.
These are all possible ways to make payment from insufficient Balanced. Bank account or cash account
Preferences
With help of Setup -> Preferences -> Allow Overdraft Limit to perform the restrictions override with this way to perform it.