Hope you are doing well and sorry to hear that.
What is the workflow/steps you are doing that lead you to this error message? A small video recording of the same would be very helpful.
Also please double check if you are using Acrobat 2015 and not Acrobat Reader DC.
If it still doesn't work,
1. Close acrobat
2. open regedit
3. goto HKEY_LOCAL_MACHINE\SOFTWARE\Adobe\Adobe Acrobat\2015\Activation
4. change "Disabled" to 1
5. restart acrobat
6. click on activate when the screen pops up
7. restart the application and check
Let us know how it goes.
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