1) You should first go to Settings > Application Settings. Uncheck the box for PDF Viewing. 2) If that does not work, then in Adobe, go to Edit > Preferences > Internet and look under the Web Browser Options you will need to make sure you have it set to "allow web viewing."

Why can't I preview PDF files?

If you don't see the Enable PDF thumbnail previews in Windows Explorer checkbox, update your Acrobat DC or Acrobat Reader DC to the latest version. To automatically update from the product, choose Help > Check for updates and then follow the steps in the Updater window to download and install the latest updates.

Why can't I modify my PDF?

Most of the reasons why you can't edit PDF files have to do with the software you are using. If you use the wrong or substandard software, you may be unable to edit a PDF document. You therefore need the best software in the business and that can only be PDFelement.