LogWorldPartitionConvertCommandlet: Error: Level contains embedded FoliageType settings

using the commandline option to convert my (huge) map intop world parttion, I get the error:

LogWorldPartitionConvertCommandlet: Error: Level contains embedded FoliageType settings: please save the FoliageType setting assets, use the SaveFoliageTypeToContentFolder switch, specify FoliageTypePath in configuration file or the commandline.

In which file, where and how (have an idea on the last but uncertain)?

Did you find any solution? I m facing this same issue

No, but I found I could use the original assets without a problem. However, if someone has a solution on what the messages exactly mean and how to solve it, that would be a great help. If only the documentation would tell me something…