New files in "DefaultData" folder not moved to "Data" folder

When launcher starts portable app it shloud copy all fles from "DefaultData" to "Data" folder if thay are not already there.
PortableApps.com Platform 15.0.2
If "Data" folder does not contain any of those files (it's "empty"), all files are copied, but if some files already exists in "Data" folder from previous run, than new files are not copied to "Data" folder.

For example:
I removed one old file from "DefaultData" with installer (complete file structure must be changed) and added new version in "DefaultData" folder.
Installer correctly removed that file from "Data" folder, but launcher does not copy this one file (now not existing) in "Data" folder from "DefaultData" folder.
If I delete ALL files from "Data" folder, then all files are copied, with that new file.

It could be tested also if only one file (of few) that exists in "DefaultData" folder is deleted from "Data" folder, louncher will not copy only that file from "DefaultData" folder.
If all files in "Data" folder are deleted, then all files from "DefaultData" folder are copied.