I've used InDesign CC a lot in the past, up until about August 2016, and have just come back to it, presumably newer version.
In preparing a document every time I add an image with transparency, or add an effect such as a drop shadow, my document stops displaying nicely - when zoomed out it's very hard to see the text at all. Display performance is set to high quality. Adding jpg images does not affect the display. What's causing this? another forum indicated it might be a CMYK issue, but it still happens if I insert a CMYK psd file, and doesn't happen if I insert an RGB jpg.
Similar issues have occurred with other document in the past week.
what is the INTENT of your InDesign document? And are you working in RGB or in CMYK mode? Did you set the Transparency Blend Space to RGB? Finally check if the Overprint Preview is turned on. If you are working in a RGB document keep the Overprint Preview turned off.