What does it mean in scripture that you cannot  "put new wine in old skins?"?

The Greek word a.skos' designates a bag or bottle made out of a whole animal skin. Jesus Christ said: "Neither do people put new wine into old wineskins, but if they do, then the wineskins burst and the wine spills out and the wineskins are ruined. But people put new wine into new wineskins, and both things are preserved." (Matthew 9:17; Mark 2:22; Luke 5:37,38)

 As new wine ferments, it generates carbon dioxide gas that exerts pressure on the skin bottles. New skins expand; old, inflexible ones burst under the pressure.

This illustration was part of Jesus' answer as to why his disciples did not conform to all the old customs and practices of the Pharisees. Jesus evidently implied that the truth of Christianity was too powerful and energetic to be retained by the old system of Judaism, which lacked vitality and elasticity and which was fast passing away. (Matthew 9: 14-16)

It means that when Christ fulfilled Rev. 14:6, the everlasting gospel of Christ being restored to the Earth in the last days by angelic ministry, he had to create a new church rather than reform an old one. 

The old, Mosaic Law and Temple Worship System were incompatible with the grace empowered, New Covenant, in Jesus Christ.

It was a metaphor. New wine expands, as it is still fermenting. Old wineskins aren't flexible enough to contain it, and they explode.

Wine bottles were made of skins. What Jesus was trying to teach is that the new doctrine that He taught was not a patch job to the old Mosaic law. The old law could not be updated with the new doctrine and people could no longer hold onto it. It had to be a completely new doctrine. Christ fulfilled the purpose of the law of Moses and now it had an end.

the skins in old times would stretch when filled with wine. if an old pouch was used for new wine it would burst the seems and ruin the wine. Thanks for the question.

to try and fix what you were doing before that didnt work

Wine was stored in goat skins, which would stretch with the fermentation process. making the skins no longer suitable for wine storage later, as the stretch limit was reached, and the skins would break.  Jesus, therefore brought a newness that could not be confined with the old forms.

No room for growth.

Deeper meaning.

Some people cannot handle the real truth when heard.

So they pop! or burst...

New skins can stretch.

Old skins cannot.

New wine could cause old wine skins to burst. It's the same example where it says not to patch a older torn garment with a new patch or the garment will be torn worse than at first. A new piece of material used to patch a hole or tear in an old garment will shrink when washed and the old garment won't shrink and the patch will tear away at the garment.