Rough surface texture
An uneven or rough surface texture.
Moisture from leaks, maintenance, spills or excessive condensation, which can cause a breakdown of the surface grain, resulting in a raised grain.
Poor quality or incorrect sanding of the flooring prior to finishing - or contamination of the lacquer or oil during the finishing process, often due to inadequate cleaning after sanding.
Correct the offending moisture source. Then lightly sand or screen the floor and re-coat as required.