2026-August-25 Service Incident

We are currently seeing elevated error rates for macOS and iOS tests in the US-West-1 data center. We are currently investigating.

After taking remedial action, all macOS and iOS tests are now performing as expected in the US-West-1 Data center. All services are fully operational.

### Dates:

Tuesday August 25th 2026, 11:38 – 13:10 UTC

### What happened:

Customers running macOS and iOS tests in our US-West region experienced degraded service. Roughly 50% of the virtual Mac capacity in the region stopped accepting new tests, so tests either queued or failed to start. Remaining capacity came under additional pressure as work shifted onto it, which extended start times for both desktop and simulator tests.

### Why it happened:

An internal security certificate used by our Mac hosts to reach a supporting cloud service reached its expiry date. Once it lapsed, the hosts could no longer establish a trusted connection to that service and stopped provisioning new test machines. The certificate had been issued manually and had neither automated renewal nor expiry alerting.

### How we fixed it:

We issued and deployed a replacement certificate, which restored connectivity and returned Mac capacity to normal levels.

### What we are doing to prevent it from happening again:

We are moving these certificates onto automated renewal and adding alerting so they are replaced well ahead of expiry, along with reviewing the surrounding tooling to make certificate handling safer.