Error: Bandmerge when i use NDVI from: GEE or SNAP

I´m new in Google Earth Engine and also in SNAP.
I´m working in delimite the snow cover area from several years following the RUS tutorial:

In one of the steps i have to add a Forest Type information, for my study area i dont have it in TIF i know in which altitude starts so i calculated a NDVI (in GEE and also in SNAP) for classified this information. But when i tried to add this information the software started to show me a warning massenge with the note:
Error: [NodeId: bandmerge] Product [sourceProduct.1] is not compatibal to master product

in both cases when i try to add NDVI (calculate in SNAP) and the NDVI calculated on GEE happens this Error
one of you have an idea why i am doing wrong? or why this happen?