If you're new to the crypto business (like me), it happens sometimes that you stumble across something that raises questions.
It happened to me a few weeks ago: I wanted to deposit some Litecoin into my favorite gambling site SHARKOIN.com, but after pasting the required credentials into my Exodus Wallet it told me: "Invalid Litecoin Address".
At first I thought I messed it up to copy the address, but the address was correct. It looked something like this: "3EGZsGuAqmWLbaxkAVMumK...".
Somehow clueless, I started to search Google and found the reasons and the solution for my problem. The Problem was "quite" simple:
"Normal" BTC addresses start with a "1". "Script" BTC addresses like multisig and segwit start with a "3".
LTC changed the "1" to an "L" so all “normal” Litecoin addresses start with an "L". The script addresses weren't changed from "3" so both Litecoin and Bitcoin shared the "3" for a while and addresses would work on both. Basically, there was no way to know if the "3" address is an LTC address or a BTC address. To fix this, LTC changed their address prefix to "M". This doesn’t break anything, it just makes it so visually the address should change and display starting with an "M".
Source: support.exodus.io
Luckily there is a simple solution for this problem: You can convert this addresses with the Litecoin P2SH Converter
This conversion works in both directions: 3xxxx -> Mxxxx and Mxxxx -> 3xxxx
As always trying first with a small amount is a good idea. Make sure that the conversion link site is authentic before using!