# After upgrading mainnet to Splice 0.6.7, validator-app fails during initialization while vetting packages. The participant rejects Replace VettedPackages serial Some(30) with TOPOLOGY\_TOO\_MANY\_PENDING\_TOPOLOGY\_TRANSACTIONS, while the currently observed st **URL:** \ **Category:** App Development\ **Tags:** canton\ **Created:** [July 1, 2026, 11:31am UTC](https://forum.canton.network/t/after-upgrading-mainnet-to-splice-0-6-7-validator-app-fails-during-initialization-while-vetting-packages-the-participant-rejects-replace-vettedpackages-serial-some-30-with-topology-too-many-pending-topology-transactions-while-the-currently-observed-st/8821 "2026-07-01T11:31:53Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![wu\_zhongxin](https://yyz2.discourse-cdn.com/flex034/user_avatar/forum.canton.network/wu_zhongxin/32/7687_2.png) [@wu\_zhongxin](https://forum.canton.network/u/wu_zhongxin)\ **Post date:** [July 1, 2026, 11:31am UTC](https://forum.canton.network/t/after-upgrading-mainnet-to-splice-0-6-7-validator-app-fails-during-initialization-while-vetting-packages-the-participant-rejects-replace-vettedpackages-serial-some-30-with-topology-too-many-pending-topology-transactions-while-the-currently-observed-st/8821/1 "2026-07-01T11:31:53Z")
Environment: mainnet Splice version: 0.6.7 Canton version: 3.5.1 Participant: Solv-Mainnet-01 Validator backend fails during app init / vet packages. validator-app error: validator\_backend app initialization: Vet packages failed ABORTED: TOPOLOGY\_TOO\_MANY\_PENDING\_TOPOLOGY\_TRANSACTIONS Too many pending topology transactions on this node. participant log: Attempting to build, sign, and Replace VettedPackages serial Some(30) packages: … 185 more TopologyManagerWriteService/Authorize failed with: TOPOLOGY\_TOO\_MANY\_PENDING\_TOPOLOGY\_TRANSACTIONS Previous symptom: check\_establish\_topology\_mapping FAILED\_PRECONDITION Condition is not yet observed Proposed: serial = 30, packages = 180 Found: serial = 29, packages = 160 We already scaled validator-app to 0 and waited, then scaled back to 1, but the same error returned. Need official guidance for repairing/clearing pending topology transactions/outbox for the participant. After scaling validator-app to 0, participant no longer logs new Replace VettedPackages / TOPOLOGY\_TOO\_MANY\_PENDING\_TOPOLOGY\_TRANSACTIONS within a 20m window. Only sequencer reconnect logs remain. However, scaling validator-app back to 1 reproduces the same vet packages failure. How to inspect and clear/repair pending topology transactions on a Canton participant after TOPOLOGY\_TOO\_MANY\_PENDING\_TOPOLOGY\_TRANSACTIONS during VettedPackages Replace. ---
**Author:** ![radevG](https://yyz2.discourse-cdn.com/flex034/user_avatar/forum.canton.network/radevg/32/7760_2.png) [@radevG](https://forum.canton.network/u/radevG)\ **Post date:** [July 27, 2026, 11:03am UTC](https://forum.canton.network/t/after-upgrading-mainnet-to-splice-0-6-7-validator-app-fails-during-initialization-while-vetting-packages-the-participant-rejects-replace-vettedpackages-serial-some-30-with-topology-too-many-pending-topology-transactions-while-the-currently-observed-st/8821/2 "2026-07-27T11:03:19Z")
Could you also provide the exact steps that reproduce the issue, starting from the last known working state? In particular: - The exact upgrade path and deployment steps - Whether the validator was running below 0.6.5 at the June 27 topology freeze - Any relevant participant or validator configuration changes - The complete first `Authorize/ReplaceVettedPackages` failure, including its error metadata - The synchronizer connection and topology-outbox status - Whether the issue can be reproduced in a clean environment or LocalNet If possible, please share a minimal repository, deployment configuration, or sanitized Helm values/docker-compose setup that reproduces the failure. Without the reproduction steps and relevant configuration, it is difficult to determine whether this is a missed-LSU recovery issue, a synchronizer-outbox problem, or validator initialization state. Since the validator appears to have missed the topology freeze, please confirm whether you have requested and followed the missed-LSU recovery instructions mentioned in the [official MainNet announcement](https://forum.canton.network/t/update-mainnet-validators-to-version-0-6-5-or-later-before-the-june-27-2026-lsu-topology-freeze/8803). There is also a [generic manual LSU roll-forward procedure](https://docs.sync.global/validator_operator/validator_disaster_recovery.html#roll-forward-logical-synchronizer-upgrade), but it requires synchronizer-specific parameters communicated by the SVs and should not be executed speculatively. I would avoid manually deleting topology state or constructing serial 30 until the correct recovery path has been confirmed. But if possible send a repo, I can review as well