duplication position

[astulaaa]

Hello,

I'm running beagle 4.1 and I'm getting this:

WARNING: Imputation of ungenotyped markers will not be performed.
Imputation requires the "gt=" argument and called genotypes.
Exception in thread "main" java.lang.IllegalArgumentException: duplication position: 1 568322 0 0
at main.PlinkGeneticMap.fillMapPositions(PlinkGeneticMap.java:77)
at main.PlinkGeneticMap.(PlinkGeneticMap.java:54)
at main.PlinkGeneticMap.fromPlinkMapFile(PlinkGeneticMap.java:154)
at main.Main.geneticMap(Main.java:360)
at main.Main.main(Main.java:109)

I checked the input file, lines themselves are not duplicated.
Can I have some advice how to deal with it?

Thanks