OIC Gen3 Error: “Error occurred during authentication” - While accessing File Server Page

Summary:

We’re encountering a persistent authentication error in our Oracle Integration Cloud (OIC) Gen3 environment when we are trying to access File Server Page:

"Error occurred during authentication. This could be a temporary issue. Try refreshing. If error persists, contact Oracle Support."

This occurs during login attempts via the OIC web console. We've tried:

• Refreshing the browser and clearing cache
• Using different browsers and networks
• Verifying IAM policies and user roles

Despite these steps, the issue persists.
Has anyone experienced this with OIC Gen3 under Filer Server Page?

• Could this be related to IDCS token expiration, OAuth misconfiguration, or backend service availability?