ExceededSlippage
SPL Token Swap · Custom(16) · 0x10
custom program error: 0x10
What it means
The swap would have paid out less than the minimum this transaction allowed (or cost more than its maximum). The price moved between the moment the quote was taken and the moment the transaction executed, by more than the slippage tolerance set in the swap.
The program's own message: “Swap instruction exceeds desired slippage limit”
What to do
Get a fresh quote and resend with the same tolerance; the price has moved on. Widen the tolerance only if it keeps failing on a fast-moving token, and know that a wide tolerance is what sandwich bots feed on.
TxWhy can repair this one
When the swap was routed through Jupiter, TxWhy replaces only the stale swap instruction with a current quote for the same tokens, amount and slippage tolerance, keeps every other instruction byte for byte, and proves the result passes simulation.
Code 16 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.