Mike,
Sorry you’re seeing this odd problem. Can you please try launching MyEclipse with a new workspace, as there may be some workspace corruption. If this works, you can import projects from your old workspace.
If that doesn’t solve the problem, can you please provide a bit more information to help us investigate?
Since this has started happening recently, can you think of any changes you made around the time this started to occur? Perhaps installing a new plug-in or some system change? Please clear the error log (this can be done from the Error Log view), replicate the problem and then export the error log to a text file (by using the Export icon in the Error Log toolbar) and attach the file to your reply.
Lastly, are you minimizing explicitly or are you simply maximizing some other view which then causes the explorer panel to minimize? Have you customized the perspective in any way? A screenshot or two would help, if you have.
Hopefully, this information will give us enough to investigate so we can sort this.
Have you considered installing the latest release of MyEclipse, in the CI 2018 series? We make frequent releases in this series so you will get all of the latest fixes and features. Note that licenses don’t relate to a particular release of MyEclipse, so you can use any release with the same license.