I have recently come across the following issue with Indesign CC 2017 on a Mac.
I am unable to click and select options in drop down boxes. When i click the box retracts but the original value remains. However i can hover over a selection with the mouse and press the space bar and it will select it.
No other computers are having this problem. I have tried uninstalling and reinstalling Indesign through the CC App manager to no avail.
If it happens on more than one file, try restoring your preferences:
If it only happens on one file, try saving as IDML and reopening:
Thanks for the quick response. The first option of trashing the application preferences appears to have fixed the issue!
I'm having this same issue, and my only workaround seems to be to uninstall the Indesign app (and deleting preferences), and reinstalling. Happening to me 2 or 3 times a week now though so my constant uninstall/reinstalls are time consuming!