Can you be a little more specific in exactly what you are doing?
Are you scaling images as you place them or scaling image or other things already on the page.
Run through all your steps.
I place the image (command+d), then as elements are added to the page if I need to re-size an image, I used to hold down the "shift" key and drag a corner of the image box inwards or outwards depending on if it needed to be bigger or smaller. That kept the proportions of the image box the same.
Now, I press command+d to place an image. After it has been placed, if I hold the "shift" key when re-sizing the placed image box, it does nothing. The dimensions of the image box will not stay at a fixed proportion. I have tried holding command+shift and option+shift while moving the image box corner, and nothing works. The only way I can keep fixed dimensions now is by using the "constrain proportions" function (manually entering sizes to make the image box change) in my top control bar.
Not to mention, when rotating a placed image box, if I held the "shift" key it would make it rotate in increments of 45 degrees. Now Holding the "shift" key doesn't do that.
It used to be so simple! I don't know what happened. I am doing the same thing that I have always done, but now it doesn't work. The only thing that changed was the version of InDesign. Is it some bug that they need to issue an update for?
Nothing has changed in InDesign CC 2017 so it's your copy of InDesign or some conflicting software which is keeping your Shift key from working.
Two things to try:
(1) Restore your InDesign preferences:
(2) If that doesn't work, reboot your computer. Launch InDesign first before any other application and try again. If it works, it means that some third party software (perhaps a Chrome plug-in or virus software or something else is conflicting.
I closed all my programs to update them to the 2017 versions and when I opened them this "shift" key issue popped up.
BUT I found the answer...apparently I needed to shut down my whole computer. Now that I have done that, the "shift" key function works just fine.