1] Change the settings in Adobe Reader

• Open Adobe Reader and click on Edit option available on the menu.
• Click on the Preference in the Edit menu.
• Select Security Enhances under ‘Categories’  in the new Preference window.
• Disable  the “Protected Mode at startup” by unticking the box under the Sandbox Protection
• Check the “Enable Enhanced Security ” option and Close.

2] Repair Adobe Reader Installation

Sometimes the Adobe reader and their resources could be damaged that will hamper the smooth functioning of the software. Here’s a quick fix to repair the  damaged Adobe reader

• Open Adobe Reader Or Acrobat.
• Click on the Help button in the menu.
• Hit the Repair Adobe Reader Installation and restart.