# Errors in Solana

Errors in Solana can be difficult to interpret. When you get a custom error, have to lookup the error code yourself.

```
SolanaError: custom program error: #3002
```

Would be

```rust
/// 3002 - Account discriminator did not match what was expected
#[msg("Account discriminator did not match what was expected")]
AccountDiscriminatorMismatch,
```

Error codes that can be returned by internal framework code are identified by its number range:

- >= 100 Instruction error codes
- >= 1000 IDL error codes
- >= 2000 constraint error codes
- >= 3000 account error codes
- >= 4100 misc error codes
- = 5000 deprecated error code

User defined errors are anything greater than 6000.

## Custom errors

You can define your own custom errors in a module. They increment from 6000 by their order of definition.

```rust
use anchor_lang::prelude::*;

#[error_code]
pub enum CustomError {
  // 6000
  #[msg("Maths not mathing")]
  MathOverflow,

// 60001
  #[msg("Maths still not mathing")]
  MathUnderflow,
}
```

## Token gotcha

> I am already using `InterfaceAccount`, I added the constraint `associated_token::mint = mint` but it gives An associated constraint was violated when i use a `Token2022` mint

use `associated_token::token_program = token_program`

## Out of room on the stack

```
"Program D4JCMSe8bh1GcuPyGjicJ4JbdcmWmAPLvcuDqgpVSWFB failed: Access violation in unknown section at address 0x109 of size 8"
```

You ran out of room on the stack. `Box` your accounts to move them to the heap.

## Too many instruction parameters

```
InstructionDidNotDeserialize
```

You can't have infinite parameters.

## Corrupt data on chain

```rust
pub struct InstrData {
    pub decimals: u8,
    pub weights: [u32; 10],
    pub inv_T: u128,
}
```

This struct is missing `#[derive(AnchorSerialize, AnchorDeserialize)]` so if you try and pass this to an instruction the data won't be what you expect.