Acrobat DC Pro Won't Open - Windows 10

[IntSol]

Dear Forum Users & Mr Adobe...
Looking at the Forum, a number of people are encountering the same issue as me...

I have had problems opening PDF files progressively over time (past 6 months) and I reached a point where none of the files I had previously opened/edited would open by double clicking the file, or right clicking the file and selecting <File Open>.  I could open via the back door, viz. Open Acrobat then open the file, however the files would eventually lock up & crash...
I recently upgraded Acrobat to 64 bit which made the problem worse, such that I couldn't open any PDF files at all.
By running the Windows Task Manager I found that Acrobat was running as a background process, force stopping it and restarting did not fix the issue...

I de-installed Acrobat and used the AcroCleaner tool for both DC2015 Pro & Reader & DC2022.

I then reinstalled Acrobat, via Adobe Creative Cloud, which automatically installed DC Pro 64 Bit.
And hey presto, I still could not open any PDFs.

After searching Dr Google I found this...
Using Fix No.4 which entails disabling Protected Mode via the Registry my problem is solved, I can now open all PDFs seamlessly...

______________________________
https://www.makeuseof.com/windows-adobe-acrobat-reader-not-opening-pdf/

The following is an excerpt from the above website...

Protected Mode is a security feature introduced in Reader 10.0 that protects users from viruses and attacks. This is a good thing for your security, but it sometimes misinterprets files as malicious and doesn't open them correctly.  (Sometimes?!)

As such, you can try temporarily turning off this mode to see if it's preventing the software from opening PDFs. Here's how to do it:

• Press Win + R to open the Run command.
  Type Regedit and tap Enter to open Registry Editor.
  Paste the following address into the Registry Editor.
• Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Adobe\Adobe Acrobat\DC\FeatureLockDown

Right-click and navigate to New > DWORD Value.

• Rename the file to "bProtectedMode."
• Right-click the file and tap on Modify.
• Change data value to 0 to disable Protected Mode.

Run the PDF file again with Protected Mode off. Keep Protected Mode off if everything works well this time instead of having to turn it on/off many times throughout the day. Of course, this will compromise your security, so it's up to you to decide if it's worth keeping off!

______________________________

Thankyou Adobe for running protected mode in the background and not telling your customers.
And I would like to undertand Mr Adobe, what is the purpose of this "Protected Mode", and who exactly is it you are protecting, your cloud??  I run both Virus & Malware Protection on all my machines.  So what is the purpose of you locking my PC down?
You are in breach of my Privacy!!

Please also note Mr Adobe you have wasted 5 days of my time this month while I have dealt with your under performing "Product".  And I now must set up all my settings (again).  Are you going to compensate me for this time??

And Mr Adobe, don't you dare modify the registry on my PC and blow my registry settings away the next time you deliver me and "upgrade"...
Can I come along and adjust the registry in your machines?  I seriously doubt it...

[Amal.]

Hi @IntSol 

Hope you are doing well and sorry for the trouble you had.

For information about the protected mode, please go through the help page https://helpx.adobe.com/acrobat/kb/protected-mode-troubleshooting-reader.html and see if that works for you.

Regards

Amal

[IntSol]

Thankyou for your rubbish response.  The link provides no solution to the problem, other than have a guess because Adobe recons it's the User's virus protection software.
Nothing to do with my antivirus software.
This problem has been occuring on 3 different PCs each running different virus protection software and different version of Windows 10.
The solution to the problem is provided in my content above, by turning off protected mode in the O/S registry...
None of the questions I raised above have been answered...

[Dawn347195585ol5]

Thank you!  This helped me so much!  I was about to trash all Adobe products and find a new PDF editor and e-signing solution.  I pay Adobe way too much money each month to continue not to even be able to open PDFs.

[ls_rbls]

Thank you for sharing your findings.

It may help many.

[IntSol]

I hope so, that's why I posted it.

In the mean time...  What is Adobe doing about the problem they have created?

[SMeurer]

been struggeling with that problem since reinstalling windows 10 a couple of months back. I have to start acrobat first, then double clicking my freshly generation PDFs by Indesign will open. I i directly wanted to open them by double clicking, the acrobat task was visible in task manager but no window. I can close the tasks, start acrbot again and can open pdfs by double clicking...

Even had to restart windows sometimes cause i forgot to open acrobat first and even killing the task didn't help to get acrobat open again. Reinstalling Acrobat several times, didn't help either. 

So, Thanks a Log for the Info, this was really helpful!

[Barney339939636uiz]

Your steps did work to fix protected mode. I encounter more problems after I could finaly get Adobe to open. I get a white rectangle shapped box with the spinning blue "circle of death" image from Win 10 in the center of the white box. It never will open a pdf file or do anything further, for that matter. This Adobe Reader version is a joke. It won't work on my Dell desktop. I've given up. Tried uninstalling, reinstalling it, repair options.....nothing has worked. Microsoft Edge browser isn't good as defualt if you need to do much with the pdf. There are few if any features to it, another joke. Moved on to something else. Something else that works, doesn't hand and does what I need it to do.

[ignacio35952561fabd]

it worked , thanks!

[hansb29475919]

WOW. Thank you. I have been flummoxed and now I am set free. I too want to get in a few choice words to Mr. Adobe but instead I will tank you for helping another traveller on this weary road.

[Eno9 · Accepted solution]

I just run into the same problem, and after trying different proposed solution, the one below worked for me:

"Close the Acrobat application and try to recreate application preferences once.

Open Windows search bar -> type regedit and open registry editor
Open Hkey current user->software->Adobe-> Delete the following keys (folders): Adobe Acrobat, Acrobat Arm, Acrobat Distiller, PDF settings & common file."

[jenniferm82502104]

This worked for me

[Donna37953260cp6d]

Thank you for this! I was getting frustrated, and this fixed the problem.