Error codes / Anchor framework
InstructionDidNotDeserialize
Anchor framework · Custom(102) · 0x66
custom program error: 0x66
What it means
The instruction data failed to deserialize into the expected arguments.
What to do
Regenerate the client from the current IDL — argument layout drifted.
Have the transaction that failed with this?
Paste its signature. TxWhy shows the exact instruction and inner call that raised the error, and rebuilds the transaction when the cause is one it can fix (compute limit, expired blockhash, priority fee, stale swap quote).
Code 102 means something else in other programs
Custom codes are private to each program. Check which program actually raised it: it is the innermost failed call, not necessarily the program you called.