When i open up 2 or more pdf documents in different tabs and start editing comments, it will stuck & hang even i let it for hours and i have to close the pdf. The result, i have lost my edited work without save it.
Could you please check for updates and repair Acrobat from the Help menu and check.
Also, check under 'File > Properties > Security' whether Editing is allowed or not.
Let me know.
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