The messgage "Can't send message with TPG - error 0" was occuring earlier this year for some people when trying to SMS. It is happening again. I'm pretty sure my account is in good order and has been operational for over 10 years.
Please check if your area has an ongoing maintenance/outage here: https://support.tpg.com.au/servicestatus
You may also have a read on some basic troubleshooting from this article: Mobile Troubleshooting
If the issue persists, send us your TPG mobile number or account number via private message for assistance.
No service outage noted in my area, Como (South Perth). Will retry again later.
I'm guessing it could be a problem at the receiving end, in Darwin.
Does "... error 0" have a more detailed explanation?
Big Oops here. I think this is my fault.
I was attempting to SMS a contact that is in my address book with only a land-line type number, no mobile number.
My error, but as suggestion: a more helpful diagnotic error message would be useful for this kind of goof.