Also make sure that jar-files are associated with Java if you want to start them with a double-click. Alternatively, you can start UMLet from the command line: cd to the UMLet directory and type "java -jar umlet.jar". (There is also a startup shell script for Linux, as well as a Windows exe wrapper.)
Found an open issue from 2016 - umlet github issue 352 - no java enum support (sorry can't post link as it's not allowed). So if you want to use this tool to generate UML from existing source code and your project contains enums, its a no go.
Looking through the log, I found "java.io.IOException: Exception in opening zip file: /home/mnl/.p2/pool/plugins/com.umlet.plugin_14.3.0.jar". Copying the file manually to that location fixed the problem (i.e. after copying, I could install from marketplace).
I am Macos Mojave user. Initially I downloaded the umlet-eclipse-p2-14.3.0.zip file, unziped and copied the com.umlet plugin version 14.3 jar file to the Eclipse plugins area but it did not work then tried to place in the p2 but it did not work.. After many attempts, I managed to install UMLet uml tool fast uml diagrams as suggested in marketplace and it worked. I created a Use Case diagram and saved it and closed Eclipse. I reopened Eclipse and tried to access my use case diagram and it hanged Eclipse and I had to force Eclipse closed. This hangs the Eclipse every time. I don't know what to do now as this is for my programming course in Australia. I have access to the error logs and I can send it if needed.
Hi -- sorry to hear that, although unfort. we are not surprised.. First, it'd probably be best for you to use UMLet standalone on macOS, or if you only need very light-weight diagrams, the online version at www.umletino.com.
This is a very nice and easy to use application. To download it I visited the next URL: www.umlet.com/changes.htm
Besides if you want to get more information, then visit the web site:
www.umlet.com
No problems to run it in Linux and Windows it's so beautiful :')