davic,
Sorry that you are seeing this problem. It appears to be an issue with Eclipse Neon and below (on which MyEclipse IDE is based) that is specific to High Sierra, but does not occur on all systems either. MyEclipse 2017 is based on Eclipse Neon 4.6.1.
We’re investigating this further to figure out what specifically causes the issue and which workarounds are possible right now.
Here are the links to the Eclipse bugs :
https://bugs.eclipse.org/bugs/show_bug.cgi?id=527171
https://bugs.eclipse.org/bugs/show_bug.cgi?id=502711
The dev team is investigating it at high priority and will let you know when we have a better solution.
Apologies for inconvenience caused. Please let us know if you have any questions.
–Swapna
MyEclipse Support