The normal vertex data is of type 'GL_INT_2_10_10_10_REV' which does not exist for GLES2, but does exists in GLES3
https://github.com/coelckers/gzdoom/blo ... s.cpp#L278
Probably best to just revert it back to GL_INT_2_10_10_10_REV then it will work on desktop and GLES3 devices.
Alternative is to modify the data to work with these types:
GL_BYTE, GL_UNSIGNED_BYTE, GL_SHORT, GL_UNSIGNED_SHORT, GL_FIXED, or GL_FLOAT