At block 325k a fork took place. Please check that both your wallet and VPS (if a masternode owner) are updated to the latest code found here
Unfortunately if you are not on the latest version of the code, you cannot recover conflicted or orphaned transactions involving coins generated beyond block 325k. You must upgrade the codebase and do a full resync of the blocks to move forward.
Coin that generated from old wallet after new wallet launch at block 325000 and after (29/7 4:40 GMT0 )=invalid coin
sent invalid coin = tx conflict
sent invalid coin + valid coin = tx conflict
repair wallet to take back your valid coin from conflicted tx
repair wallet not take back your invalid coin from conflicted tx
add reysncron and make sure