# Increased Function Invocation Errors - ERR\_MODULE\_NOT\_FOUND

- Provider: [Vercel](https://down.guide/vercel)
- Level: confirmed
- Impact: Degraded
- lasted 2h 10m
- started 2026-05-18 21:42 UTC
- id: DWN-02ac32f047
- Official page: https://stspg.io/6knpl12q53h5

## Updates from Vercel
### 2026-05-18 21:42 UTC: investigating
We're investigating an issue where customers are currently experiencing application failures due to function invocation errors when using React Router 7.

### 2026-05-18 21:53 UTC: identified
The issue has been identified and a fix is being implemented.

### 2026-05-18 22:11 UTC: identified
We're continuing to work on rolling out a fix. In the mean time, customers may use Instant Rollback to a previous deployment version as an immediate workaround in order to recover.

### 2026-05-18 22:16 UTC: monitoring
A fix is rolled out for the function invocation errors affecting React Router 7 deployments. To recover, redeploy your application or use Instant Rollback to a previous deployment from the dashboard. We're continuing to monitor.

### 2026-05-18 22:19 UTC: monitoring
We are continuing to monitor for any further issues.

### 2026-05-18 23:52 UTC: resolved
This incident has been resolved.
Some deployments created between May 18, 2026, 06:15 PM - 10:16 PM UTC may have experienced increased ERR\_MODULE\_NOT\_FOUND function invocation errors due to a bad rollout. Deployments created outside of this window are unaffected.
The fix is being rolled out to existing deployments retrospectively and is expected to finish in the next few hours.

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