Negative Lab Balances

A negative lab balance is likely due to simultaneous studies being run on the account with slightly not enough funding (on the TurkPrime end). When this occurs, TurkPrime doesn't stop live studies that have insufficient funding, rather, we post a negative lab balance to be funded at a later time (before the launching of additional studies). 

Once the lab balance is back at zero, you should have no problem launching more studies.