Why isn't drag n' drop working like it used to?

It matters as an example of an app by Apple where drag and drop of images no longer works. Remember, you mentioned that you can only test with native Apple applications.

I am only having problems with dragging and dropping if I am trying to drag and drop between applications that have been compiled for different system versions, dragging from a Sierra application to a pre Sirra application. third-party applications or older applications, built for older system versions might be a part of the problem for dragging text as well.

First, you're welcome. I'm on Mojave right now so I can't check High Sierra for a few but, I selected a line of text which included a link in Safari and Mail and could drag them to the Desktop which creates a text clipping.

As far as Preview, I can't drag text anywhere with out without links.

Of course copy & paste works.

Drag and drop of photos between older applications does not work even for dragging from Photos to older Apple applications, if they did not get an update after Sierra came out. For example, I cannot drag a photo from Photos to iPhoto 9.6.1.

IF you select text in Safari with a hyperlink included and then click and hold on that hyperlink, you can drag it, but otherwise it just deselects the text.

I don't see that running Mojave or High Sierra. It still drags and drops just like it always did.

I dropped into Pages and Word, dragging by the hyperlink portion of the selected text.

Same with Mail IF the hyperlink has been "processed" by being sent

What does that mean? I composed a new message and both typed a link and added a link. Both could be dragged and dropped.

Preview doesn't work at all, no matter what.

No, it doesn't.

First, as I said I had no problems dragging images between iPhoto 9.6.1 and Photos 4.0 while running Mojave. And the OP is not having an issue with drag and drop between versions compiled for different systems. He's having an issue with the latest version of Preview since Sierra, in which dragging and dropping no longer works. Which Barney and I both found to be the case.

I'm done.

Most welcome. If you need to drag text from a pdf You can use a different PDF reader such as Adobe Reader or Skim.

My guess is seeing drag n drop works on ten's if not hundreds of millions of Macs running High Sierra that's not exactly what you mean by "working like it used to".

What does "working like it used to" mean to you? drag n drop works the same for me and I'm sure millions of others the same way it always has for the most part.

Okay. I just tried Preview in El Capitan. And I can drag and drop text. So Preview has changed in it's functions since El Capitan but drag and drop itself works "as before" for files and folders and for me in Safari. So "for the most part".

"I iterate: IF I WANTED PC FUNCTIONALITY, I'D HAVE BOUGHT A PC!!!"

I agree. I am working on PC everyday, Windows10 and it is great !

But I also work on Macs, and I have never had an issue with drag and drop, all OS and macOs until HighSierra (I am still waiting on the 2nd update of Mojave before I upgrade). It is still the same. Of course, drag and drop directly between partitions and between MacOs and Windows (either in a virtual machine or in a windows partition) does NOT work, and has never worked. I have no idea what your issue is caused by.

But can you drag and drop directly from the Photos 3.0 or 4.0 browser into the open iPhoto window? On High Sierra and Mojave I have to drag from Photos to the Desktop and from there to iPhoto or Aperture. I can drag from Photos into a "New Mail" window or a Keynote presentation without problems, but not into the iPhoto window or Aperture window. Dragging and dropping from Aperture to iPhoto or vice versa is possible. Photos seems to require a certain protocol to allow drag and drop, and the recipients need to be updated to follow this protocol and support it.

Yes. I can drag an image from Photos 4.0 into iPhoto 9.6.1. I don't know why any of this matters since iPhoto is no longer supported so even if it didn't work for me it would be no surprise. This really has nothing to do with the OP anyway.

Same issue. Used to be able to drag and drop from Preview to Pages and now it says the file doesn't exist. Terribly frustrating as I often want to include information from a Preview doc into a Pages one. Never had this issue before I upgraded to Mojave..there has to be a simple work around.