Resolving FlexCard Access Error: "Failed to get rollup module" for Guest Users in Experience Cloud

When attempting to view an OmniStudio FlexCard on an Experience Cloud (Community) page, unauthenticated Guest Users may encounter a component rendering failure. Even when standard permissions, OmniStudio licenses, and sharing rules appear to be configured correctly, the following error message is thrown:

Error: Failed to get rollup module for forceGenerated__flexCard_TestFlexCard___salesforce___1___false: Unknown Exception

Note: This error is isolated to unauthenticated users; authenticated internal or community users can view the same FlexCard without experiencing this issue.

This issue occurs due to insufficient object-level permissions on the Guest User Profile.

OmniStudio FlexCards rely on base components and data sources that require underlying read access to specific standard objects (most commonly the Account object) to initialize and render correctly. Even if the FlexCard does not directly display Account data, the underlying OmniStudio architecture may evaluate contexts that require this baseline access. When the Guest User Profile lacks Read permission on the Account object, the compilation fails, resulting in the "Unknown Exception" rollup module error.