It's a runtime upgrade to migrate the balance state of all accounts based on the token decimal change (12 -> 18).
Please refer to this release:
https://github.com/litentry/litentry-parachain/releases/tag/v0.9.19-02
The migration code:
https://github.com/litentry/litentry-parachain/blob/52022d983e8212fd95f8b14f897c7945f8d74882/runtime/litmus/src/lib.rs#L141-L150