Ok, I have read all of the forums related to this issue and no one seems to have come up with an actual solution. I have the latest versions of OSX and Acrobat DC. In Safari I get the message: "PluginProcess.app wants to use your confidential information stored in "v4.services.acrobat.com" in your keychain" whenever I try and access a pdf online. The three choices are Always Allow, Deny or Allow. Clicking on Always Allow or Allow does nothing. Only clicking on Deny makes the window go away, but that is only temporary. Like many other people you have to click on Deny 5-20 times to get the pop up window to go away.
To Adobe Staff: Your suggestions to click Allow or Always Allow does not work.
I have deleted v4.services.acrobat.com in my keychain, without success (another forum suggestion).
Does anyone have a solution, other than spam clicking Deny?
Edit: I have noticed that it only happens in Safari, not Firefox (haven't tried Chrome yet). Can anyone else with this error confirm whether they are using Safari or not?