In the Windows of non-English European language setting, a comma "," is often set as a decimal point.

In such an environment, after opening an input file, if you click "Run poptree" box with an option of "Distance/Phylogeny", nothing will happen.
(However, if you choose "Heterozygosity/Gst", the results of computation will be shown with no problem.)

If you experience this problem, please choose a period "." as a decimal point in the "Region and language" setting of Windows.
If you do this, "Distance/Phylogeny" option should work.

This is an adhoc solution. We are sorry for the inconvenience. We plan to fix this problem soon.