Hi tda
Thank you for your post. Welcome to the Community Forum.
There are two things to check here: the account and the tax code used. I suggest going to the Accounting menu >> Chart of Accounts >> Look for 4-1010 and check how it is set up. You need to make sure you're using an Income account with the right Tax Code. If you're using INP or GNR, this can result in that error. You may want to use N-T if this is a Sale with no GST. This Help Article, Tax Codes, will give you more information on how to use and manage different tax codes.
We still recommend that you seek advice from your accounting advisor or the ATO regarding how tax should be applied in your circumstances.
Please feel free to post again. I'm happy to assist further.
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