This error will appear if the Foreign pension or annuity income at item 20 is incomplete. Firstly, open the item 20 worksheet and check the Foreign pensions or annuities fields:

If the taxpayer did not have any Foreign pensions or annuities then please remove any zeroes from the fields shown above. In the example above, deleting $0 from Foreign pension or annuity foreign tax paid will resolve the error.

If the taxpayer did receive a Foreign pension or annuity then refer to the "Claiming foreign pensions or annuities" knowledge article. 
 

To claim foreign pensions or annuities using the item 20 worksheet, you will need:

• Details of the foreign source income.
• Assessable foreign source income.
• Exempt foreign employment income (enter $0 if there is nothing to report).
• Foreign pensions or annuities gross amount.
• Foreign pensions or annuities deductible expenses (enter $0 if nothing to report).
• Foreign pensions or annuities undeductible purchase price (amount needs to be greater than $0; otherwise leave it blank).
• During the year did taxpayer own, or have an interest in, assets located outside Australia which had a total value of AUD$50,000 or more?

If the gross or net amount is displayed at item 20L (Net foreign pension or annuity income WITHOUT an undetected purchase price) then you will need to manually enter $0 at item D11Y Deductible amount of undeducted purchase price of a foreign pension or annuity.

If you are claiming an amount at item 20D, the undeductible purchase price needs to be greater than $0. The undeductible purchase price amount will automatically transfer to item D11Y.
 

The guide below will also resolve the validation error, CMN.ATO.GEN.XML04 - A mandatory field has not been completed.
The element 'ExemptForeignIncome' in namespace...

When claiming foreign source income and foreign assets or property at item 20, you must complete:

• Details of the foreign source income.
• Assessable foreign source income label E.
• Exempt foreign employment income (enter $0 if there is nothing to report).
• During the year did taxpayer own, or have an interest in, assets located outside Australia which had a total value of AUD$50,000 or more?
• The relevant section for the foreign source income.

Please note, you need to create a separate worksheet for different sources of foreign source income.

If you need to report Employment income - non PAYG then,

1. Leave Exempt foreign employment income blank.
2. Enter Foreign income employer name.
3. Enter Gross employment income under Employment income-non PAYG.
    

Firstly, check the ATO's prefill did not import data into the item 24 category 1 worksheet for lump sum payment. If it did, please delete the worksheet.

Complete the two lump sum fields in the income worksheet (item 1 worksheet).
•    Lump sum code
•    Lump sum amount - lum sum year and lump sum amount

The lump sum amount will automatically transfer to the newly added item 24 lump sum amount field. The software will also include $0 at item 24 category 1 to pass validation due to the new validation rules in the 2020 tax return.

On item 7 worksheet, leave the type blank to be able to manually enter the tax offset at item T2.

Additionally, you can create a new line on the item 7 worksheet and skip to the offset column to enter the amount.