As mentioned you are getting error 523:523, could you please check if an update is available for Acrobat/ Reader using "Check for updates" option under "Help" menu, reboot the machine after installing update and try again.
If that doesn't work, try temporarily turning off "Protected Mode at startup" as the following thread suggests and try again?
Please note: Disabling protected mode is for troubleshooting purpose only, and not recommended. Please turn the feature back on after troubleshooting is complete.
Please refer to the following help document for more info on Protected mode:
Also, could you confirm the application- Reader or Acrobat and the operating system you are using?
Let us know if you need any help.