Error building custom QGC

I renamed custom-example as custom, cleaned my previous build and also ran python code. While building the code i faced this issue:

Code Snippet:
for (int i = 0; i < _flightModeInfoList.count(); i++) {
FlightModeInfo_t& info = _flightModeInfoList[i];
//-- Narrow the flight mode options to only these
if (* != _holdFlightMode && != _rtlFlightMode && != _missionFlightMode) {
// No other flight modes can be set
info.canBeSet = false;

sounds like one of the variables in the != statements is a QString, rather than an std::string, etc.

so you need to find which one is the QString, and call toStdString() on it.