If your PDF will not open, try this. Start Internet Explorer. On the top menu select Tools, Internet Options. You should see the following
Select Manage Add-ons
Adobe Acrobat Control for…
sure it is the one that says “ActiveX Control” in the Type column.
Next select Disable, click OK to the warning you receive. Next select Enable, click OK to the warning you receive.
Then click OK on the Manage Add-ons screen you see above. You will be back at the Internet Options window.
Click on the tab marked General on the far left. Click on Delete Files to remove cached web pages. After it finishes, the hour glass will stop and your cursor will return- click OK.
You must now close and restart Internet Explorer and you will be able to see PDFs in CM/ECF again. Be sure you close all IE browsers if you have more than one open.