You can try to check if your Internet Explorer is configured to open the PDF files. When you install Acrobat or Adobe Reader on a system that includes a browser, you automatically configure the browser to open PDF files within the browser window. Acrobat
and Adobe Reader install ActiveX plug-in files that allow you to use Internet Explorer PDF files. If PDF files don't open in the browser window, work through the following steps to configure the browser:
To configure the browser to use Acrobat or Adobe Reader to open PDF files:
1. Quit Internet Explorer.
2. Start Acrobat or Adobe Reader.
3. Choose Edit > Preferences.
4. Select Internet in the list on the left.
5. Deselect Display PDF in Browser, and click OK.
6. Restart Internet Explorer.
I also suggest that you download the PDF file save it and try to open to check if Adobe Acrobat is working fine.
You can download a PDF file to the hard drive from a web page's link. Downloading PDF files doesn't require the ActiveX plug-in file to be installed. (If you want to open and view the PDF file after downloading it, you must have Acrobat, Adobe Reader,
or Acrobat Reader installed.)
To download a PDF file from a link:
1. Right-click the link to a PDF file, and then choose Save Target As from the pop-up menu.
2. In the Save As dialog box, select a location on your hard drive, and then click Save.
You may also refer the below link that will give you instructions on
General troubleshooting if your receive Internet Explorer cannot display the webpage: