"open an old can of worms", what does it mean ?

Question

"open an old can of worms", what does it mean ?

Answer 1

Its "opening a can of worms," and means getting into something you're going to find very distasefull.

Answer 2

Don't mention a certain subject. It could lead to a conversation topic that is going to be unpleasant.

Two more  with the same meaning

"Let sleeping dogs lie"

"If it aint broke don't fix it "

Answer 3

to bring up a touchy situation that was supposedly already solved

Answer 4

It means a source of many unpredictable or unexpected problems.

Example:

Buying a company we know nothing about would be opening up a whole new can of worms.  

Answer 5

it means you are bringing up something that has all ready been said and done.. so there for leave it alone.

Answer 6

It means to bring an issue to the public eye, creating a problem even bigger, bringing out other related issues that otherwise could stay hidden. Example: Jose Canseco with his book "Juiced" opened an old can of worms about the steroid use in Major League Baseball.