The issue is caused by “security mechanisms” of OS X. In order to circumvent / expose the users PATH variable, knime must be started via command line by:
Navidating to the executabel via cd /Applications/KNIME.app/Contents/MacOS/
Start knime via ./knime
However, this comes with a not so insignificant disadvantage as the terminal must, under any circumstances, being kept open. If close by accident, knime is immediately stopped (not properly shut down).
Adding to this. the start up window seems to not list the loaded / installed extensions. However, they are still accessible (bug or feature?)
I’d like to propose to enable defining / overwriting the PATH variable manually in the External Nodes. Similar to how it was made possible by @AnotherFraudUser in AF Utilities (big thanks!)
Reason is, the “security” measure might get in this or another way implemented by other OS vendors too. The struggle which many had to go through to identify the cause would be easily avoidable but also would allow to add a significant amount of flexibility in defining binaries.
Quick question, though. You post has been marked as the solution but that is yet not available. It will result in this topics getting closed before a solution becomes available which could confuse current and future readers.
Since the solution is depending on a ticket / update, wouldn’t it be, for the sake of comprehensibility, an idea to link solutions not just to workflows but also version updates / nodes?