I have a similar issue in that the guide listing on my LG 70UF770T doesn't show any data (EPG) until i click 'preview' for each channel. After calling the store (Harvey Norman) this same behavior occurs on other 2015 LG models so presumably it is a software problem. If this is not a bug and is how LG expect users to operate the guide it is really poor.
As per milenceto123's post, this has not been a problem for other tv's including other LG tvs and windows media centre etc which all load the EPG successfully.
Thanks.