I am an 84 year old academic, who has developed scientific software since 1961. In 2007 I developed a java-8 application that is running worldwide as a jar. To give the software a life-expectancy beyond my own, I have now updated the program as a Gradle build and placed it on Github [https://github.com/Papa-26/GS_LV). I can generate installers for Linux, Windows and Macs - but there is the rub! I can build, install and run the application on my own Mac, but as soon as it moves to another Mac, I get the ugly message: "GS_MV" is damaged, and can not be opened .... move to trash!. That even happens, when I upload the installer to Google Drive, and then download it again to my own machine. I have searched various fora to find a solution - for naught. Does it mean that I have to pay a ransom to Apple, in order that colleagues can run the free software on their Macs?