Adobe Acrobat does not open when opening .pdf files. Instead, multiple running instances are opened in the background.

Hi @agile_Melodya052,

Thank you for flagging this and for including the "end task" workaround, which is helping people in the meantime. Seeing this recur across multiple users over months is frustrating, and we want to help you get to a lasting fix rather than a repeated workaround.

What you're describing, a PDF not opening visibly while an Acrobat process sits in the background, sounds similar to a documented issue we have on file. It lists four possible causes: leftover unresponsive Acrobat background processes, an incorrect Windows registry entry tied to Acrobat's file-open handling, an outdated Acrobat version, or a corrupted installation. Full details for each are here: https://adobe.ly/3TiK1ln.

To help point you to the most likely cause across your users, could you let us know:

1. Are the affected users on Windows, macOS, or a mix? (The registry-based fix in the article is Windows-specific.)

2. Are they on Acrobat Reader or Acrobat Pro, and roughly which version (Help > About)?

3. Did this start after a specific Acrobat update, or has it been intermittent the whole time?

That'll help us narrow down which of the four causes is most likely behind the surge you're seeing.

Please share these details, and we'll take it from there.

Thanks,
^BS