# Runtime release notification for v1.5.0: Kusama finality lag \[10.05.2025\] **URL:** \ **Category:** Tech Talk\ **Tags:** runtime-releases\ **Created:** [May 10, 2025, 11:37am UTC](https://forum.polkadot.network/t/runtime-release-notification-for-v1-5-0-kusama-finality-lag-10-05-2025/12861 "2025-05-10T11:37:30Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![anaelleltd](https://dub1.discourse-cdn.com/flex005/user_avatar/forum.polkadot.network/anaelleltd/32/7664_2.png) [@anaelleltd](https://forum.polkadot.network/u/anaelleltd)\ **Post date:** [May 10, 2025, 11:37am UTC](https://forum.polkadot.network/t/runtime-release-notification-for-v1-5-0-kusama-finality-lag-10-05-2025/12861/1 "2025-05-10T11:37:30Z")
**Runtime release notification for Validators and Ecosystem builders** Hello, Following the execution of the [v1.5.0](https://github.com/polkadot-fellows/runtimes/releases/tag/v1.5.0) upgrade on Kusama, a change was introduced to enforce switching from [V1](https://github.com/paritytech/polkadot-sdk/blob/51e29401648c23aedeab8c4219d1051a772a1143/polkadot/primitives/src/v8/mod.rs#L514) to [V2](https://github.com/paritytech/polkadot-sdk/blob/51e29401648c23aedeab8c4219d1051a772a1143/polkadot/primitives/src/vstaging/mod.rs#L66) of the `CandidateDescriptor` primitive used by parachain consensus and exposed in the events `CandidateBacked` and `CandidateIncluded`. However, a bug caused the system to fail under disputes, instead of disabling the V1 validators that started the disputes. [Kusama Referendum 524](https://kusama.subsquare.io/referenda/524) has been submitted to disable V2 descriptors node feature to avoid 1.16 and older nodes triggering disputes when validating candidates using V2 descriptors. We are concurrently rolling a fix to restore finality on Kusama. 🚧 **Important note for Polkadot validators:** 🚧 Please do not upgrade to this version, as the node will not run on Polkadot. Many thanks.