I´m studying the tutorials in indesign and I can´t pick up the idea of what a missing file is even though I can follow the steps of the video
in which the concept is explained. Could you please give me a real example about this issue? In the video they replace a graphic file with a stop sign which comes with the downloaded .indd document with a file placed in the links folder in my PC that was also downloaded from the tutorial in order to follow the explanation? I don´t see any changes when the replacement takes place. It look like as if they were the same files. I see no difference, just the name of the file changes when the file is incorporated into indesing.
Haven't seen this tutorial, but it sounds to me like they are showing an example of what happens when a file that is linked in a .indd file that you are placing into a second .indd is not available.
In such cases the program has no access to the data in the missing file (typically linked files are some sort of image, but they can also be pages from other .indd or PDF files used like an image) and would not be able to properly render that data for output. Usually this means that the low-resolution screen preview is used instead, but sometimes there is no screen preview either and you'll get a gray box.
You are more likely to notice a missing link problem on screen if the Display Permormance is set to High Quality Display.
Here the top image was placed on the page, and then moved to a different folder, so its Status shows as Missing—InDesign can’t find the original. The bottom image has not been moved and its Status is OK.
Both images display their low res preview proxy, but if I try to export or print the page, the top image will not output at a high resolution because the original link is missing and the low res proxy prints instead.