Are you by any chance trying to load a save file from New Hope level 2?
There was a bug in 0.12.25 making saves for New Hope 2 unplayable which was fixed for 0.12.26, but you need to restart that level on 0.12.26 for it to work.


Bugfixes

Fixed the corrupted level 2 of the New hope campaign ...

0.005 2016-03-06 17:12:52; Factorio 0.12.26 (Build 17762, win64)
0.006 Operating system: Windows 10
0.007 Program arguments: "C:\Program Files (x86)\Steam\steamapps\common\Factorio\bin\x64\Factorio.exe"
0.007 Read data path: C:/Program Files (x86)/Steam/steamapps/common/Factorio/data
0.007 ...