Less files error with less version 4.1.0

Using less version 4.1.0 webpack gives an error in the timeline,grid less files(not sure about others,these 2 I got errors at).
the error is just the lines where “floor” is used.

Error evaluating function floor: argument must be a number

the lines are: @className: floor(@value);

Upgrade to F7 v6.0.3, or downgrade less to v3