'Transaction too large' ?
When you try to send a transaction your wallet system will take many inputs to get the amount necessary to finish the transaction. In this process, your wallet will make a new addresses to return the change.
So after a while, your wallet will have many addresses, with many low balance, and if you try to send a new transaction, the wallet will select those addresses, and if it selects more than 100 addresses, you'll have that error message,
Here's a few ways of how to fix:
1. You'll have to enable your Coin Features and select all inputs by yourself:
Just go to Settings / Options / Wallet -> Enable coin features
Then return to 'Send' and click in inputs.
You can't do this using 'terminal systems'
2. You may need to regroup all balances in one address:
Select the highest inputs in the coin features ( 1. ) and send them to one address.
3. Send spliting your balance (eg. if you send 100 and still have error, send 50, and so on... )