My old installation of Workbench went inexplicably wrong, so I tried a fresh install of Eclipse & Workbench. Looks good until I try Documentation Build, when I get the following error:

An internal error occurred during: "Launching EcoEvo Paclet Build". java.lang.NullPointerException

I also tried starting a new project and got a different error on Documentation Build:

Specified VM install type does not exist: org.eclipse.jdt.internal.launching.macosx.MacOSXType

Any ideas?

Eclipse Version 2018-12 (4.10), Workbench Version 10.1.822, Mathematica Version 11.3, MacOS Version 10.14.3.

  • $\begingroup$ My biggest frustration with Workbench is that is fails unpredictably. I remember creating a project, doc build failed. I created another project with the exact same steps, then it worked ... I don't know if this is related to the problem you ran into, just mentioning that similar things happened to me too. $\endgroup$
    – Szabolcs
    Mar 19, 2019 at 8:24
  • $\begingroup$ I have observed that Workbench is less prone to errors when using java 8 (which is the same as 1.8) rather than the latest SDK. Try using java SDK 8 (1.8) but make sure that it is this version of SDK that is actually being used. I had to modify eclipse.ini for that. For me, documentation build simply didn't work at all with null reference exception before I switched to SDK 8 :) $\endgroup$ Mar 19, 2019 at 9:02
  • $\begingroup$ @Anton.Sakovich Thanks for the idea, but switching to JDK1.8 didn't help. $\endgroup$
    – Chris K
    Mar 19, 2019 at 9:11
  • $\begingroup$ I am happier since I abandoned WWB. I don't need to create docs but I imagine it is less painful to cook something up with all alternatives people posted around. $\endgroup$
    – Kuba
    Mar 19, 2019 at 10:47
  • $\begingroup$ @Kuba I use it solely for creating documentation. If I were starting from scratch, I'd try something else for sure! $\endgroup$
    – Chris K
    Mar 19, 2019 at 10:50

1 Answer 1


I solved the second problem by installing a JRE into Eclipse as described here.

I solved the first problem by re-reinstalling Eclipse. Not sure what changed -- maybe I was more careful in eliminating remnants of the previous install (.metadata folders)? maybe I used the right workspace directory? We may never know!


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