Nope, that doesn't seem to be WB related. If WB starts it writes something along these lines
WORLDBUILDER_COH_2 started at 2013-10-27 09:24
OS NT 6.1 (sp1.0) x64, 12205MB Physical Memory, 8889 Physical Available, 4095 Virtual Total, 3947 Virtual Available, 12203 Page file.
RUN-OPTIONS []
WORKING-DIR [D:\Games\Steam\SteamApps\common\Company of Heroes 2]
USER [Christian]
LOCALE [DEU]
09:24:40.47 Primary CPU is a 3601MHz [Intel(R) Core(TM) i5-2500K CPU @ 3.30GHz]
09:24:40.47 Architecture [0], Level [6], Revision [10759].
09:24:40.47 4 logical processor(s) detected.
09:24:40.47 4 physical processor(s) detected.
09:24:40.47 1 processor(s) nodes detected.
...
I fear i am out of ideas for now.
Actually, maybe you installed Steam within your program files folder? Windows handles that folder with special care and you might not have writing permission, even as administrator.