Error: Failed to load acquisition chart sample is missing axis "accX"

Hi Team,
i have accelerometer and humidity, temperature data in the data acquisition. using flatten and classification blocks and saving the impulse. after went to the next step, i was hitting this error below:
Error: Failed to load acquisition chart sample is missing axis “accX”

i gone through this Environmental sensor fusion - Edge Impulse Documentation
tutorial to understand sensor fusion and tried with temperature, pressure, & humidity with the flatten & classification, also given the same error as above mentioned.

  1. how do we combine multiple sensors data and make an inference model out of it? please anybody help me.

Thanks,
Venkatesh K.