Plugin errors regarding plugin or class not found

[youngzh]

I drag and drop the java file onto "ImageJ" window and then click file>>Compile and Run. But it says "Plugin or class not found: "FST_Tool" (java.lang.ClassNotFoundException: FST_Tool)"

You can find the code via the link.

https://git.mpi-cbg.de/mosaic/MosaicSuite/blob/ad927ff8e5f9267c4ce130bb5330f88ade5ac477/plugin/src/mosaic/plugins/PSF_Tool.java

I wonder what's gooding on?

Many Thanks,

Yang