I was switching between a couple projects in a designer today (when one project is open, select File -> Open) and when the new project opens up some of the components are missing and can not be selected. Container in the Misc tab, all of the components in the Alarming tab and all of the components in the Admin tab. If I close the designer and reopen it then they are all back and can be selected no problem. FYI.
Ignition version 7.6.2
Java version 1.6.0_24