It won’t be solved quickly as in within a week. It may be solved this month, but first someone needs to debug it and then fix it, plus some testing period.
Last weekend I used RarePepeWallet with my Counterwallet pass phrase, and I was able to send BTC from it (it uses a different approach to compose transactions). The reason for Counterwallet having issues with the address may be that it had many unspent outputs (> 100).
I see your address has 16 (http://redeem.bitwatch.co) so that may be why. 16 isn’t huge, but it may be why.
Too bad it (RarePepeWallet) is not available for testnet, because I have a testnet address that is having this “insufficient BTC” problem and could be used for troubleshooting.
Apart from RarePepeWallet, Indiesquare can be used as well (works with Counterwallet pass phrase) and you can also try CounterTools or even (if you want to send BTC) Bitcoin Core (import private key, but you’ll have to do a rescan of the entire blockchain which may take whole day on non-SSD disk, assuming you have a copy to begin with).
This weekend I’ll troubleshoot that testnet address to see if I can find more about this problem.
If you could report which one worked for you, that’d be nice.