Error codes / 0xc6
custom program error: 0xc6
Custom(198) · 0xc6 · used by 1 program we know
This number has no meaning on its own. Each Solana program numbers its own errors, so 0xc6 is MissingImmutableOwnerExtension in Metaplex Token Metadata. The meaning that applies is the one from the program that actually failed: the first Program … failed line in the transaction's logs. That is often not the program you called, but one it invoked, or a guard instruction your wallet added.
Don't guess: paste the transaction
TxWhy reads the logs, finds the program and the exact instruction that raised 0xc6, explains it, and rebuilds the transaction when the cause is one it can fix.