what's the main problem with the barter system of exchange?

what's the main problem with the barter system of exchange?

I think the main problem of barter system is that you can't find the exact value of a thing you want to exchange.
For you want to buy a TV which is worth 2 fridges and a pan, but you only have one fridge and a pan.
What to do in such a scenario?
That's of course a very simple example but I hope it shows the nature of what I tried to say :)