Sch C Wks (Casual Clothing) -- Form 568, p 3-5: Depreciation and amortization should be left blank if none. Do not enter zero. But I can't leave blankit reverts back to 0

Same problem here.  Spent hours on the phone with different reps.  None of them can explain it but then they dump you into a black hole or forward you to talk to a Tax Expert for $90.  No thank you.  TurbuTax, please just fix this problem.

This appears to be a TurboTax error, and a blocking error that will prevent many filers from completing their return.

If you entered Assets in your 1040 Sch. C, which happen to add up to zero depreciation, this information passes the Federal review and is imported into the state return.

Turbotax *automatically* adds that zero total to Form 568 line 17a.  During state review, you are advised that zero is not permitted *even though Turbotax added it*.  Furthermore, Turbotax disabled the field you need to change in that review and correction process, and further denies any attempt to remove the zero from that blank (contradicting their explicit instructions).

This is a big problem that TurboTax must solve or it will wreck filing for many affected customers.

having the same problem, very annoying

This is just a wild guess based on no facts. But it "sounds" like you mistakenly entered inventory as an asset. Then realizing your error before you completed the asset entry process, you dumped out of that part of the program - thus leaving an incomplete asset entry.

So go to the Business Assets section and if there's an asset listed on the asset summary screen that shouldn't be there, click the Delete button to the right of it and delete it.

If that's not it, let me know and I have one more thing to check and try.