Hi Roka, I am using 2019.1.0f2 as well and the programs are working in my tests. Could you please try importing the program into a new project to see if it is possibly a conflict with another application. In the last update I refreshed all the meta data files to prevent Unity from installing them into the same folder, but if you have an older version of one of my programs then this may be causing the window to appear blank. If this is the case then the solution is to copy the whole Mesh Cutter folder from the new project into your working project and you should find that the programs work fine together. I have had an email from a customer who had a problem where the programs were having trouble reading their settings files (.xml type) and were throwing an error reading the values. This appears to be caused by a regional issue which affects some number types being read incorrectly using XML. Are you using a different language to English or other configuration that may be causing a problem? There is a forum post talking about this issue here at https://stackoverflow.com/questions/8348317/why-receive-formatexception-on-valid-double-input and a workaround here at https://support.microsoft.com/en-in...curs-when-attempting-to-convert-a-numeric-str I am working towards an update for the end of May to support some now obsolete methods in Unity and will try to remedy the regional problem as well as a few other fixes. I hope these suggestions help fix the problem but if you find that the problem persists then please write to me at email@example.com and I'll do my best to help.