Issue opening PDFs in proclaim. default viewer is set to Adobe Reader for adobe docs but when you open a PDF in Proclaim it uses Nitro Pro which is an installed Adobe editor.
Opens a pdf outside of proclaim it will use adobe reader, it's only pdfs within proclaim which are affected.
PDF opens in Nitro from inside Proclaim
If the file association is correct on the user's pc, it is a window's issue that is causing the problem. To resolve, follow the below:
Open Registry Editor
Navigate to:
HKLM\Software\Classes\.pdf
Change this entry under (Default) to open in Adobe by matching the entry found in HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.pdf\UserChoice\ProgId
Close Registry Editor
Open Proclaim and test
If you are unable to access Registry Editor, please contact your IT and ask them to carry out the above instructions.