HotKeyAlreadyRegisteredInSubNet
Error v151 → v212, v216 → v219, v233 → v315, v320 → current 7.21Why This Error Exists
A hotkey can only hold one UID per subnet. If you're already registered, there's nothing more to do - you can proceed directly to staking, setting weights, or running your miner/validator. This error is often a false alarm indicating your previous registration actually succeeded.
Deep Dive
Registration assigns a UID to your hotkey on a specific subnet. The Uids map stores (netuid, hotkey) -> uid. Once registered, you stay registered until pruned (replaced by a better-performing neuron) or you unregister. Trying to register again is redundant - you already have your slot.
Debugging Example
You call burned_register(netuid=1, hotkey=5Xyz...). Error: HotKeyAlreadyRegisteredInSubNet. Query Uids(1, 5Xyz...) - returns 42. Your hotkey has UID 42 on subnet 1. Solution: Skip registration and proceed with add_stake, set_weights, or serve_axon.
Prevention Tips
- Query Uids(netuid, hotkey) before calling register
- If it returns a number, you're already registered
- Handle this error gracefully in scripts - it's often a success condition
From Chain Metadata
The caller is requesting registering a neuron which already exists in the active set.
What This Means
This hotkey is already registered on the specified subnet.
Common Causes
- Attempting to register a hotkey that's already registered
- Previous registration succeeded but you didn't see confirmation
How to Fix
- Check SubtensorModule.Uids to confirm registration status
- If already registered, you can proceed with other operations
- Use a different hotkey if you need another registration
Storage to Check
Thrown By
Version History
Runtime Info
- Pallet Index
- 7
- Error Index
- 21
- Error Code
- 7.21
- Runtime Version
- v411