There is an issue with the staking-mechanism that needs to be addressed.
I have a working copy of the blockchain from 2 May 2017.
A few days after the above date, I did a large transaction to another wallet.
The client went off-line for a while.
When I started it again, it went into staking the entire sum and got stuck.
I also tried to mine again, but the peer on the other side didn't accept my blocks.
Recently I experimented with a truncated version of the chain.
I used one client for mining. Another one was staking for hours.
..
A huge amount of coins disappeared.
checkwallet didn't report any errors.
The old chain from 2017 now has been mining for two days.
So far, no POS blocks since I do not dare put any old wallets on-line again - just in case.
I believe it once was planned to get rid of staking altogether.
Of course, making transaction, staking or mining without previously completing blockchain syncronization will not work.
New mined blocks were not valid, transactions also rejected.
"checkwallet" is only checking the integrity of the file not the amount in the wallet.
To fix your problems :
-backup your wallet
-download blockchain
https://mega.nz/#F!BcYWGIAD!gqtg334lPCN-CHwVDoRsyw and latest release
https://github.com/strcoin/starcoin/releases/tag/v1.7.1.0-str-add a copy of your wallet in starcoin folder
-also in starcoin.conf file must add staking=0 if you want to stop staking in order to make transactions with all your coins
-for wallet check, and recover all your valid coins and mined blocks, start with -rescan option
( path/starcoin-qt.exe -rescan ) , it will take awhile but you will obtain the exact and real state of your wallet.
-if you did spread coins in many wallets, do that for each one
Don't do anything (transaction, mining) before completing blockchain syncronization.