When you open a file that is too large or unsupported by the IDE, you receive an error alert message. This makes sense, but I find it to be extremely obnoxious when coupled with the file-preview feature accessed via single-click. If I double-click a file, an error message is appropriate, but if I just click on the file to select it (usually in order to download or drag-drop), it should not barrage me with error messages. These alerts frequently lock up the IDE and require a page refresh to unlock.
As a compromise, maybe print a message to a passive status bar at the bottom/top, or a passive pop-down from the top that’s the size of the message, but does not interrupt the user’s action.