i have not used QGis in a long time ,however i normally use Nip2 ( a gui to the vips image library )
it is a cross between Excel and Gimp and it has math functions that i use to normalize a image to 0-65535

the vips image lib
https://github.com/libvips/libvips/releases

and the nip2 gui
https://github.com/libvips/nip2

there is a bit of a learning curve to using this software and i normally forget about seeing as i have been using it for many years


but as to your error

it might be a issue with GDAL
QGis is after a front end to GDAL

What Operating system are you using and how did you install Qgiss and GDAL