Anchor
ConstraintSigner
“A signer constraint was violated”
An account marked Signer did not sign the transaction.
Common causes
- The wallet you passed as a signer was not added to the transaction's signers.
- A PDA was passed as a
Signerinstead of being signed viainvoke_signedin a CPI.
How to fix it
- Add the keypair to
.signers([...])or let the wallet adapter sign. - If the signer is a PDA, pass it as
UncheckedAccount/SystemAccountand sign with seeds in the CPI.