This usually means that someone else has already claimed your dependent. They may have even claimed themselves. For confidentiality reasons, the IRS is unable to disclose who that person is. For more information please click the link below.

TurboTax Online instructions for E-file reject R00 ...

See if this post helps for which ssn was rejected

https://ttlc.intuit.com/community/after-you-file/discussion/how-do-i-find-out-which-ss-is-already-us...

The -01 probably means the first dependent listed.