Are you sure you haven't accidentally applied a crop preset at Import? Go to the History panel in the Develop Module and look at the bottom entry there, if it says Import and the date and time, then no preset has been applied. If it says Import/<preset name> and a date and time, then you have applied a preset.
Camera is an Olympus OMD EM-5. When I import none of the preset are activated. As you said, it says import and the date and time in the history panel. Camera should have taken a 4608 x 3456 picture, instead I see in properties it is 4608 x 2596 But, why when I open it with windows it opens the 4x3 picture, and opened in adobe I see a 16:9 cropped picture? I don´t know. I´m sure this information is somewhere...
Another thing I noticed, when I open propertyes of the image in windows it says image is 13,4 MB (14.106.680 bytes), when I open it in LR it says 11,9 MB... I even have instaled LR again thinking it could be damaged...
this is the pict seen in the windows view, as you can see there is plenty of ble sky above the cloud, and you can see a forest.
this is the same file opened in LR, as you can see pict is cropped.
Now I realized, the pict above is like compressed, maybe the files are corrupted?
and here you can see all files (they are part of a timelapse) in 4x3 previsualization...