Employer did not tell me that I had to invest my 401k myself.

We have an office with 10 people and 9/10 people have their 401k money invested by the financial institution we are under. I have been there for some time and have a good chunk of money in my 401k. I have not kept track of it(which I should of, I know) and my statement are all electronic. I looked at my online account and noticed all of my funds were all cash and nothing has been invested in the market. I called the rep and he said that my account is non-discretionary and I am supposed to be buying my own stocks. Started talked to other people at the office and they said all of their accounts have been invested…and they do not do it.

What is the catch? Did my company/financial institution just forget about my account?