Uploading attachment (via file browser on Attachment macro) on a page with Team Calendar macro results in misleading error message

Issue Summary

Misleading error message ( Error(s) occurred) would be shown on the Confluence UI when trying to upload an attachment (via file browser) with the Attachment macro, on a page with Team Calendar macro embedded to it.

Steps to Reproduce

1. Add a Team Calendar macro and Attachment macro to a Confluence page.
2. Attempt to upload a file via the Attachment macro using the file browser option.
3. Notice a misleading error thrown in the Confluence UI.
   Should you reload the page, notice that the attachment is indeed being uploaded successfully to the page.
   The same issue is not reproducible via drag and drop option.

Expected Results

The attachment is uploaded successfully without any error message.

Actual Results

The attachment gets uploaded successfully (only listed on the page after the page is reloaded) with a misleading error message thrown in the UI.

Workaround

Upload the attachment via the Attachment macro using the drag and drop option.