downloading pdf's from the web are unreadable or "damaged" since latest windows update.

If in fact what is being downloaded from Dropbox is a file named test.html, then in fact it is a file that Acrobat Reader cannot open. Acrobat Reader opens .pdf files, not .html files. Something must have changed in your browser configuration and/or whatever those web-based assessment tools generate for download.

This is not an issue with Acrobat Reader. As previously suggested, ascertain within the Dropbox window that the file is indeed a .pdf file. You may try using the Dropbox interface as opposed to the web browser one to access the file and ascertain that it is a .pdf file.

Hi MuggysBroista

We are sorry for the trouble. As described you are unable to open the PDF and getting the error 'Adobe Acrobat Reader could not open 'test.html' because it is either not a supported file or because the file has been damaged.'

Is this a behavior with a particular PDF file or with all the PDFs? Please try with a different PDF file and check.

Please try to download the PDF file to your comouter locally and then try to open it with Adobe Acrobat Reader and see if that makes any difference.

What is the version of the Adobe Acrobat Reader you are using? To check the version go to Help > About Adobe Acrobat Reader and make sure you have the latest version installed. Go o Help > Check for Updates.

You may also take a look at the help page https://helpx.adobe.com/acrobat/kb/pdf-error-1015-11001-update.html and see if the steps works for you.

Let us know how it goes

Regards

Amal