SoilJ: open folder with tiff images

I selected the folder, but I get this error:

(Fiji Is Just) ImageJ 2.0.0-rc-71/1.52p; Java 1.8.0_211 [64-bit]; Windows 10 10.0; 81MB of 12125MB (<1%)

java.lang.IllegalArgumentException: Stack is empty
at ij.ImagePlus.setStack(ImagePlus.java:686)
at ij.ImagePlus.setStack(ImagePlus.java:675)
at SoilJ.tools.InputOutput.openTiff3DSomeSlices(InputOutput.java:850)
at SoilJ_.PoreSpaceAnalyzer_.run(PoreSpaceAnalyzer_.java:164)
at ij.IJ.runUserPlugIn(IJ.java:230)
at ij.IJ.runPlugIn(IJ.java:193)
at ij.Executer.runCommand(Executer.java:137)
at ij.Executer.run(Executer.java:66)
at java.lang.Thread.run(Unknown Source)