I created a dump with mongodump on computer A (ubuntu 12.04 server). I moved it to computer B (ubuntu 12.04 server) and typed:
mongorestore -db db_nam
Got same problem on debian 7 without locale-gen (command not found) installed.
I solved this way:
su apt-get install locales dpkg-reconfigure locales # select locales you want!
Now mongodb should start.
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