Adobe DC has been broken for the last 2 months

Are you getting any erros at all?

Did you contact support at all so they can check what could be the problem?

In any case, based on the screenshot that you shared, it looks like this is happening in every MS Windows computers according to your observations. 

Are all of these computers using the same operating system or is it also occuring in different versions of MS Windows? 

Conversely, are all those Windows computers using the same exact version of Adobe Acrobat Pro DC or different version updates?

Is Adobe Reader and Adobe Acrobat Pro installed concurrently in the same computer(s) that are showing this issue? If yes, is the Adobe Reader version newer or older than the Adobe Acrobat Pro version or vice versa?

However, It appears to me as if the AcroCEF executable is blocked by the Anti-Virus or Firewall service.  If that would be the case, we cannot assume the service is broken.

Have you tried whitelisting the AcroCEF executable in MS Windows Defender and see if it does any different?

See if these Adobe Helpx Guidance are relevant to resolving the issue:

• https://helpx.adobe.com/acrobat/kb/acrocef-rdrcef-errors.html
• https://helpx.adobe.com/acrobat/kb/RdrCEF-exe-and-AcroCEF-exe-can-I-disable.html   <<<------- note in this link where it briefly explains that AcroCEF "handles Document Cloud services (like Fill and Sign, Send For Signature, Share for view/review, and so on)". With that in mind, does the service stops working every time a document is sent for signature? Shared for review? or using the Fill & Sign Tool, for example?