One thought is that you should add your AC version as well as your platform to your signature. Just because you have few posts we can't assume you are on AC12, or that this project is in AC12. Many still use older versions of AC.
This is not an idle request. If you are on AC11 we would be able to instantly rule out that the dimensions 'disappeared' because you placed them when 'core only' was active and yet the view's active Partial Display Option was for 'entire structure'. This feature is only available in 12.
That aside, with text disappearing as well as dimensions it might also be that you placed the text and/or the dimensions on a layer(s) that although visible when working in the view was not a layer set to show with the View.
Try turning on all layers and setting them to show in the Layer settings box cmd/ctrl+L, and find the missing text and dimensions. check their layers.
If they are not there, perhaps you or someone else inadvertently deleted them or the layer they were on?
Or perhaps the file was closed without saving?
We've all done these things when learning and in haste
Erika
Architect, Consultant
MacBook Pro Retina, 15-inch Yosemite 2.8 GHz Intel Core i7 16 GB 1600 MHz DDR3
Mac OSX 10.11.1
AC5-18
Onuma System
"Implementing Successful Building Information Modeling"