InvalidParameterException when subsetting the specific font

[jan.tos...@gmail.com]

Dear All,

when trying to subset a large DroidSansFallback.ttf font, I am getting (Win 7, JDK 8):

>java -jar sfnttool.jar -s world D:\DroidSansFallback.ttf D:\test.ttf

Exception in thread "main" java.security.InvalidParameterException: CMap Id settings would generate font with no cmap sub-table.

        at com.google.typography.font.tools.subsetter.Subsetter.setCMaps(Unknown Source)

        at com.google.typography.font.tools.sfnttool.SfntTool.subsetFontFile(Unknown Source)

        at com.google.typography.font.tools.sfnttool.SfntTool.main(Unknown Source)

It works fine for e.g. Palatino. 

Is there any workaround for this?

Thanks, Jan