Got Error Message when I use schCheck with sstatus(errsetTrace t)

Hi Sirs, 

When I use schCheck(CV) to do check&save in my script, I got error mesages below. 

schCheck(CV)
*Error* hiSetProgressBar: argument #1 should be a window type (type template = "wx") - nil
<<< Stack Trace >>>
(... in _schProgressBarStep ...)
processed = nil
win = nil
step = 12
item = 1
numberOfItems = 1
(... in _schSetBatchProgressBar ...)
step = 12
numberOfSteps = 12
item = 1
numberOfItems = 1
apply('_schSetBatchProgressBar '(12 12 1 1))
(... in schExtractConn ...)
nError = nil
nWarn = nil
result = nil
errL = nil
sumErrors = 0
sumWarns = 0
sheetCV = nil
sheetInst = nil
sheetList = nil
errMsg = nil
severity = nil
msgPrefix = "Extracting"
checkAll = nil
inGraphics = t
id = nil
didList = nil
checkHierIgnoreNeedCheckout = nil
runPreCheckTrigs = t
cv = db:0x2f20f71a
(... in schCheck ...)
result = nil
result1 = nil
result2 = nil
nError = nil
nWarn = nil
userErrorWarn = nil
totalError = nil
totalWarn = nil
cvId = db:0x2f20f71a

I found when I set sstatus(errsetTrace t) I got those mesage. I can set sstatus(errsetTrace nil) to make all error messages disappeared.  However, do I have any other way to make there is not any error message?

Thanks.