FixedSupply
SPL Token · Custom(5) · 0x5
custom program error: 0x5
What it means
This mint has no mint authority — supply is fixed.
What to do
You cannot mint more of this token.
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 5 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.