Customer impact

Between September 11, 2026 at 14:56 UTC and September 11, 2026 at 20:45 UTC, a subset of customers could not deploy solution packages in Solutions Management. Deployment attempts failed during package generation with a compatibility error indicating that a package version was not compatible with the expected Application runtime version.

The impact was global across production environments and lasted approximately 5 hours and 27 minutes. Community environments experienced related impact beginning at 14:56 UTC.

Root cause

A regression in an internal component that manages software package versions caused the failure. During solution package generation, this component provided an incompatible package version, which caused a framework compatibility check to fail and blocked affected deployments.

Detection

The issue was first reported by a customer and then reproduced internally. The incident was created. The team confirmed the failure as a package compatibility error.

Response

At 18:42 UTC, the team identified the deployment error as a compilation failure caused by an incompatible package version. The mitigation strategy was to restore the affected component to a previously known-good version.

The restore began taking effect by 18:50 UTC. By 19:16 UTC, monitoring data confirmed the restore was progressing and the incompatible version was clearing. At 19:47 UTC, the public status page was updated to reflect that the issue was identified and the fix was in progress.

Recovery was slower than initially expected because the restored component is only loaded when customers restart their designer session, rather than immediately upon deployment. The restore completed across all regions at 20:45 UTC. The incident was marked resolved after monitoring confirmed recovery.

Follow up

• Short-term, delivered. Keep files in cache for every runtime version in use rather than only the newest, so a rebuild would no longer delete files robots depend on.
• Short-term, to do. Add automated end-to-end test coverage to the deployment pipeline that validates package cache integrity before rollout, blocking releases when tests fail.
• Short-term, to do. Add automated monitoring and alert to cover NuGet package cache missed that fail to be resolved either from cache or from the source.
• Longer-term, in progress. Stored dependency results are now validated against their cache and discarded when referenced files are missing, so a stale result can't be reused against a mismatched cache — jobs fall back to downloading at run time rather than failing.