When viewing PDFs in Edge (IE mode) or Internet Explorer, you may encounter an error dialog stating, “There is a problem with Adobe Acrobat or Reader. If you have reinstalled Acrobat or Reader, please exit and try again. (0:521).”

This issue tends to occur frequently when switching to a different PDF while viewing a PDF within the browser.

The issue persists even with the latest version 2023.008.20421 as of the time of posting.

For the 32-bit version, disabling protected mode and extended security seems to prevent the issue from occurring. However, for the 64-bit version, similar setting changes do not resolve the error.