You may need to load the wallet address twice. Once to load the ETH transactions and then a second time to load the Alt Coin transactions.
You will load the same ERC20 public wallet address both times. 

So, take your MEW public address that you can find here:

Then to load the ETH transactions:
-Click on the Zenledger logo on the top left
-"Wallets" on the right
-"Go to Wallets" in the middle
-Desktop Wallets
-Select Ethereum from the dropdown
-Enter your MEW public address
-Click "Add Wallet"

Then to add your ERC20 Alt Coin transactions, while still on this screen:
-Select "Altcoin ( 3500+ Coins)
-Enter your MEW public address
-Click "Add Wallet"

Go To Wallets:

Select "MyEtherWallet"

Select from the dropdown

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