The message means, for the Invoice Misc. Charge type you have selected, you must enter the same amount in the Venture Details Tab. However, If you do not have an associated Venture or PO yet (because this is a deposit invoice), it would make sense that you can not do this. If this is the case, go to the System tables – Invoice Miscellaneous Charge types and select ‘edit’ for this charge (the charge for the deposit)
There is a column that says ‘non venture misc charge’ and the current setting is No. Change this to Yes. Update the charge type. Then go back into your invoice, remove the charge and add it again, it will not give you that error message.