# Overflow (/docs/errors/chain/Overflow)

A checked arithmetic operation overflowed, e.g. incrementing `NextSubnetLeaseId` when registering a leased network, or adding to a crowdloan's `raised` amount or contributor count. Internal guard; inspect the amounts involved as this should not occur with realistic values.

Declared by the `SubtensorModule`, `Crowdloan` pallets; it classifies to the semantic code [`internal`](/docs/errors/internal).

## Remediation [#remediation]

A chain-side invariant failed; nothing to fix client-side — report it if it persists

The same explanation is available in the terminal: `btcli explain Overflow`.