Hello, i have a problem

When i change my Excel Tables with the data of Air Temperature, RH, Wind velocity, and Global Radiation from Excel, and let RayMan calculate the PET values, it change the value for the Global radiation to 9999, as if there is a missing value.
I tried to run the data set without the radiation from measurements (so it will use the G-values from my location) it does work, but the diffrences are too high. I typed the G-values of the measurement in the Input file by hand, and it worked aswell.
So how can I change this problem, that the txt data from excel will appear as missing value, but the txt data, where i fill in the global radiation by hand works fine?