There is two main reasons why either SimpleWallet or GUI wallet rejects a transaction even if there is enough unlocked coins in the wallet:

1. The transaction contains too many inputs
   This can be caused either by too high anonymization level (mixin) or the wallet hasn’t been optimized recently.
   To fix this, first optimize the wallet (either enable wallet optimization in settings of GUI wallet and wait until the optimization status in the settings says the wallet is optimized, or open the wallet in SimpleWallet and run “full_optimize” command).
   If optimization doesn’t remote the error, lower anonymization level until the daemon accepts the transaction. If it still fails at level 0, continue to next step.
2. The wallet is out of sync
   This can be usually fixed by resetting the wallet and making sure the node daemon can be connected from other nodes. Daemon needs port 33802 open from internet through any firewalls (including NAT) and routers. If you can’t open ports, you need to use remote daemon to synchronize the wallet. IPv4 must be enabled and DHCP must give valid IPv4 address to the machines running node daemon and wallets.

If you have multiple machines in local area network running wallets, use single machine for the node daemon and connect to that instance from all wallets. Both SimpleWallet and GUI wallet allow using remote daemons. Compare the blockchain height displayed by wallet with blockchain height reported by official blockchain explorer. In SimpleWallet, you can see blockchain height with command “bc_height”.

Sometimes when starting GUI wallet, it reports "Blockchain load error" and doesn’t open. There is easy fix to this that doesn’t require deleting whole blockchain and resyncing from height 0.

In Windows, the GUI wallet configuration file and blockchain data files are stored in hidden directory, so Explorer must have hidden directories set as visible. This is usually in the right most menu in Explorer where there is three tick boxes on top of each other on right side of the toolbar. The lowest one is for showing hidden files and directories. Go to your profile directory, then "AppData", "Roaming" and "Talleo". If the "Talleo" directory does not exist, you must create it and make text file named "TalleoWallet.cfg" inside it.

In Linux, the data files are in directory ".Talleo" inside your home directory, if it doesn’t exist, you need to create it and make text file "TalleoWallet.cfg" inside it.

For Windows, contents of the file should be something like this (replace "postm" with your real Windows username, this should be same as the directory name under "C:\Users"…

{
    "connectionMethod": 3,
    "minimizeToTray": false,
    "miningPools": [
        "pool.raasu.org:3333",
        "pool.talleo.org:3333"
    ],
    "optimization": {
        "enabled": true,
        "mixin": "0",
        "showOptimizationTransactions": true,
        "target": "100000000"
    },
    "privacyParams": {
        "newsEnabled": false
    },
    "recentWallets": [
        "C:/Users/postm/AppData/Roaming/Talleo/Talleo.wallet",
    ],
    "remoteRpcUrl": "pool.raasu.org:33888",
    "walletFile": "C:/Users/postm/AppData/Roaming/Talleo/Talleo.wallet"
}

For Linux, contents of the file should be something like this:

{
    "connectionMethod": 3,
    "minimizeToTray": false,
    "miningPools": [
        "pool.raasu.org:3333",
        "pool.talleo.org:3333"
    ],
    "optimization": {
        "enabled": true,
        "mixin": "0",
        "showOptimizationTransactions": true,
        "target": "100000000"
    },
    "privacyParams": {
        "newsEnabled": false
    },
    "recentWallets": [
        "/home/postm/.Talleo/Talleo.wallet",
    ],
    "remoteRpcUrl": "pool.raasu.org:33888",
    "walletFile": "/home/postm/.Talleo/Talleo.wallet"
}

If the file already exists, you only need to change the lines containing "connectionMethod" and "remoteRpcUrl". This will make the GUI wallet load the blockchain from one of the seed nodes to memory instead of storing it on local disk. You can also use "pool.talleo.org:33888" for "remoteRpcUrl", but that will slow down the official mining pool if many users use it.

Make sure you save the wallet private keys or export the wallet to another location before you close the GUI wallet as saving the wallet might fail if it is stored in same directory as the blockchain.

The "optimization" section will control automatic wallet optimization and when enabled, try to make sure maximum usable amount in wallet is as close to 1 million TLO as possible. This will make new transfers smaller and less likely to be rejected by network. Value of "target" should always be power of 10.