URL with invalid urls.primaryName loads default page without error notification

Swagger UI does not notify user when URL refers to an invalid API name eg
https://demo.caspio.com/integrations/rest/swagger/index.html?urls.primaryName=Caspio+REST+API+v3+NotExist
load the default API page and does not notify the user about the problem

• OS: Windows 11
• Browser: Chrome
• Version: 143
• Method of installation:
• Swagger-UI version: 5.11
• Swagger/OpenAPI version: 3.0

Content & configuration

Navigate to the invalid link
https://demo.caspio.com/integrations/rest/swagger/index.html?urls.primaryName=Caspio+REST+API+v3+NotExist
and notice that no error feedback is provided to the user.

Describe the bug you're encountering

No error feedback to user when URL / query param is invalid

Steps to reproduce the behavior:

In the browser, open the invalid link
https://demo.caspio.com/integrations/rest/swagger/index.html?urls.primaryName=Caspio+REST+API+v3+NotExist
and notice that no error feedback is provided to the user.

Expected behavior

An error or popup indicating that the part of the URL that is invalid

Screenshots

See above

Additional context or thoughts

None

Reproduce the issue by opening the provided Swagger UI URL with an invalid urls.primaryName query parameter. Trace where that parameter is handled and how the default API page is selected. Done means an invalid API name produces visible error feedback instead of silently loading the default page; verify the behavior in Chrome with the supplied URL.