My ex filed her taxes on one of my children and she wasn't supposed to claim him she went back and amended her taxes I went to try to file and I was rejected

[xmasbaby0]

You do not have to wait for her amended return to be processed.   The duplicate use of the child's SSN means you cannot e-file this year.  Go ahead and claim the child if you are the parent who can claim him, but you need to file by mail now.  Your e-files will be rejected no matter how many times you try.

When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s.  Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS/state received the return.

Federal and state returns must be in separate envelopes and they are mailed to different addresses.  Read the mailing instructions that print with your tax return carefully so you mail them to the right addresses.