Modifying page content in a plugin fails with 7.15

To answer myself:

We are also running in the issue mentioned here

So we can retrieve the old content and modify it just fine, but we aren’t able to actually update the content with ContentService.update()

I can’t believe there is NO working sample or even samplecode that shows how to reliably modify page content via either the old or the new Java API - seems that’s just something plugin developers aren’t supposed to do.