I was motivated to move to whatever version of Java supported multi-line strings, e.g.

String myStr = """
123
456
hello
""";

and the first long term support version was apparently 17+.

We routinely test (e.g. UTs as actions) with versions from 8 through to 23 (not every version), and 17 is not exactly new.

So, it seemed like a good bet...

However, moving to 17 led to as yet unseen problems, in particular, UI-related errors like this on my Mac:

2025-12-23 19:05:59.605 java[83868:44261771] GLDRendererMetal command buffer completion error: Error Domain=MTLCommandBufferErrorDomain Code=8 "Insufficient Memory (00000008:kIOGPUCommandBufferCallbackErrorOutOfMemory)" UserInfo={NSLocalizedDescription=Insufficient Memory (00000008:kIOGPUCommandBufferCallbackErrorOutOfMemory)}

This happened at start up initially, preventing the main window from opening. After a search, the following seemed to fix it:

-Dsun.java2d.metal=false

but it showed up semi-randomly, e.g. when selecting a list item chooser in a dialog box or opening Preferences.

There are also what used to be warnings in 8 that now appear to be errors in 17.

Before settling on trying to resolve problems with VStar+17, trying the next LTS, 21, may be simplest. So, I did that, and it didn't seem to be any better.