error in callDMR(): Error in if (class(DMLresult)[2] == "DMLtest.multiFactor") flag.multifactor = TRUE: missing value where TRUE/FALSE needed

[teryyoung]

Error in if (class(DMLresult)[2] == "DMLtest.multiFactor") flag.multifactor = TRUE: missing value where TRUE/FALSE needed
Traceback:

1. callDMR(dmls_long, p.threshold = 0.01)

I have run callDML successfully, but error with callDMR(); I checked class(dmls_long)[2], it does is NA, it that normal?