Same mistake last year and I had to file via paper. Please fix this error. Alowance for the Survivor is not taxable. It is to be to be added line 146 and deducted line 250.I hope this can be fixed, I liked turbo tax prior to this problem.
Can you tell us which version of TurboTax you are using, please? And is it installed in your computer by CD/Download, or is it Online?
If you are reporting the Allowance for the Survivor from the T4A(OAS) slip that has been issued to you, then you will be able to NetFile your tax return. Only if this allowance is being issued to you on a T4A(OAS) slip and you are not between the ages of 60 to 64, will it cause a NetFile error.
Both Social Assistance payments from a T5007 slip and GIS payments from Box 21 of the T4A(OAS) slip are non-taxable and reported on your tax return in the Total Income section, then deducted to arrive at "Taxable Income" on Line 250.
https://turbotax.intuit.ca/tips/the-guaranteed-income-supplement-5513