Why won't my password be accepted with trying to install adobe reader?

I just had the same experience. Now it has been resolved. Just quit the process and retry with the same mac password which had not been accepted. 

Does it make any difference if you download the full installer from Adobe - Adobe Acrobat Reader DC Distribution and use it?

So, you get the SAME prompt from some other software install (except for the app name) and it works? If so that leads direct to my worry, and my question: where did you download it?

NO. Nothing is wrong with the Reader app (or at least, this does not show it).  This prompt comes from the Mac itself. (Basically, the installer says "I would like to install software to the system, please do this for me", the Mac asks for the password, and if the password is right, the software is installed - by the Mac itself - into the system. Adobe software doesn't see the password at all, it's between you and the Mac.

So if your Mac password is not accepted you have a very serious problem. You would need help from a Mac expert, not an Adobe software expert.

There is one other possibility, an unwelcome one, that this is malware pretending to be Acrobat Reader, putting a fake password prompt, and sending the password to bad people. It is only a small possibility. Where did you download it?

you're probably being prompted for you mac's password.

[moved from Installing, Updating, & Subscribing to Acrobat to Acrobat Reader]