Diagnosing base URL configuration problems
Operations in the Universal Plugin Manager (UPM) seem to hang; a warning message appears on the page indicating that "the base URL configuration of your instance is inconsistent with the URL in your browser."
What's going on:
Most of the content displayed on the UPM page is loaded dynamically via AJAX requests. Most of the requests to the system use relative URLs, which will function correctly whether or not your instance's base URL is configured properly. However, by design, some long running operations (for example, add-on / app installation and upgrade) make requests using absolute URLs. If your instance's base URL is not configured properly, the UPM will display a warning informing you that the base URL of your instance may be misconfigured.
If an error related to base URL mismatch occurs, there may be no indication of a problem while performing an operation in the UPM. However, the UPM may not be able to display the progress of the operation. If you refresh the UPM page, you should see the result of the operation in the audit log.
In other cases, the interface may display the following error message: "The URL being used to access the application in the web browser must match the one provided at the Base URL configuration"."
In order to fix the problem, you may need to update the base URL settings in your instance. See the following product documentation pages for instructions: