Reimbursement for corrupted staking ledgers

SUMMARY

The Polkadot runtime upgrade to v1.1.2 introduced an unintentional breaking change that prevented three staking accounts from receiving staking rewards across multiple eras. This proposal seeks to reimburse these accounts for the rewards they should have earned for backing validators and securing the network.

The process was detailed by core developer gpestana in multiple articles compiled in the following Polkadot Forum post:

Recover corrupted Staking ledgers in Polkadot and Kusama

The referendum could not be proposed until the runtime upgrade to v1.4.0, which corrected the balance state of one of the affected accounts (PR 538).

TIMELINE

2024-02-19 Breaking change introduced in runtime upgrade v1.1.2
2024-03-15 Hotfix on runtime upgrade to v1.1.3.
2024-10-15 Runtime upgrade to v1.3.3 set the correct ledger/stash status.
2025-02-26 The balance issue for one of the accounts was corrected on runtime v.1.4.0.

PROPOSAL DETAILS

Each account faced a unique situation, and the analysis took into account the bonded funds at the time rewards ceased, the number of eras the payee account went without receiving rewards, and the average APY during that period.

Below is the information for each affected account:

Affected account: 138fZsNu67JFtiiWc1eWK2Ev5jCYT6ZirZM288tf99CUHk8K

Payee account: 12YcbjN5cvqM63oK7WMhNtpTQhtCrrUr4ntzqqrJ4EijvDE8
Last era with rewards: 1400
Last bonded balance before not receiving rewards (DOT): 8,556
Last era with no rewards: 1597
Eras without rewards: 197
Average APY during that period (%): 17.18
Missing rewards (DOT): 1,603.46

Affected account: 15bt67qghz8hJxCUPgAXmzVxUBHLpPN41RVm2nwMFyLWByVE

Payee account: 15bt67qghz8hJxCUPgAXmzVxUBHLpPN41RVm2nwMFyLWByVE
Last era with rewards: 1646
During era 1526, the stash account 14kwUJW6rtjTVW3RusMecvTfDqjEMAt8W159jAGBJqPrwwvC was wrongly scored with 0 in the 'voterlist'. However, the account 15bt67 kept receiving rewards until era 1646. During era 1683, the account 14kwUJ 'voterlist' score was updated and the same account started to receive rewards at era 1684.
Last bonded balance before not receiving rewards (DOT): 4,261
Last era with no rewards: 1683
Eras without rewards: 37
Average APY during that period (%): 12.93
Missing rewards (DOT): 587.11

Affected account: 12gmcL9eej9jRBFT26vZLF4b7aAe4P9aEYHGHFzJdmf5arPi

Payee account: 12gmcL9eej9jRBFT26vZLF4b7aAe4P9aEYHGHFzJdmf5arPi
Last era with rewards: 1402
Last bonded balance before not receiving rewards (DOT): 7,110
Last era with no rewards: 1613
Eras without rewards: 211
Average APY during that period (%): 16.96
Missing rewards (DOT): 1,313.76

Polkadot had a problem with its software update, which stopped three staking accounts from getting rewards. A proposal has been made to give these accounts the rewards they missed out on. The proposal looks at how much money was in the accounts when the rewards stopped, how many times they didn't get rewards, and how much the rewards would have been worth during that time. Here are the details for each account:

Account 138fZsNu67JFtiiWc1eWK2Ev5jCYT6ZirZM288tf99CUHk8K:
- Last reward: Era 1400
- Last balance: 8,556 DOT
- Missed rewards: 197 eras
- Average yearly reward: 17.18%
- Missing rewards: 1,603.46 DOT
Account 15bt67qghz8hJxCUPgAXmzVxUBHLpPN41RVm2nwMFyLWByVE:
- Last reward: Era 1646
- Last balance: 4,261 DOT
- Missed rewards: 37 eras
- Average yearly reward: 12.93%
- Missing rewards: 587.11 DOT
Account 12gmcL9eej9jRBFT26vZLF4b7aAe4P9aEYHGHFzJdmf5arPi:
- Last reward: Era 1402
- Last balance: 7,110 DOT
- Missed rewards: 211 eras
- Average yearly reward: 16.96%
- Missing rewards: 1,313.76 DOT

Source