@Christoph-Hart Ok I figured out how to trigger it consistently. Run this snippet in any project that has expansions. It's the call to refreshExpansions after the call to unloadExpansion that is causing problems.
HiseSnippet 862.3ocsU01aSiDDdcZMhj6EARv2s3SoRPTxAWAIDhRSR4xczRzkB5jPmPaWOtYUWuq0tqKMBUo6m78OfaFa2XmR.ghNhhhyLyyy5mY7LimZMBv4LVVP6iWjArfeLb1Bse9v4bolMYDK3tg4ZkgGO9hLt1IM5iAmms+hLtyAwrffsdIAMn81rhO+6y2mq3ZAT6hwdqQJfWISk9ZuS26OjJ0A7X3XYZCzOZuIBidnQYxQYsUXeVFWbF+T3HNAqUHK3Fiikdiclm6AGKX68MwKlM27AcI92JcxST.YLfMCOnR2GXTwjhIurgykp3oWk9NFdJSqKFaUVLtS3gxX4R+0EkaUDHplQy5QPqUk2VqHuAMkW+FxaMRJngj1tTR2NblvJy70QH87CgSzdvlvwxdSoThk05AsBGZPDZeuT9YvAVzXIit61u+8ive14oc5fkdmOBtH6235XEXidVzX8oRMzSXALeV1FTEuKRZImWIwqOqA6dmB9kLnnD7NRsBOvnjbsvi9iL58y8did.oQqQ0UXRyLZTs2O5btJG1oyG6zVlD0sxpMZ1VYDbUDTd+ny9c8+6mh9wuDToaDjf2l3tvNHiBJsgdWqYlzC4uVwVHwBt4KQ3JgbIAqCd4RLAtpVhY2vqjZ26UkD2amdNxeQpLjqTmfsucudNhGZi7+HiGdMJFJO6bYmnqGJIYswpNqhGCqILMWY+ZD6pySOArMqxDPrYa0N3vubGbyALQYYoAPidhV5ecFn+RicrpZI9u2LYD2yo19JeHtLv5kjDBFAmi6PJGBZGNBbm4MYEXqd.fqE7EQ+4pQjxBNSFSDpp9rKpWz7t8Vrz3e988jtCMo34vsn6fVN94vD8TrW.7znD6ymEws.l3bE2u5pAZeXU.rZux7HMygcU9EM2W9+19huUId6voRuX950Xq0nQ7Yx2CMVsk8mBGmj.Bes.2N7f+56yJU1eZx8R8oGx8VI1KDdTd5L7EMB.u6ZMnnt8fVTeYocexlp.y.cbgwmvOUAGP1AUAGbUPVJWXMuWTNiQ6wuYgGTS5hWg0N7PxNZ.qXtC4E1uWeVJ9Jk2KDT5+.bTY8b9kMfyC2.NOZC37qa.mc2.NOdC37juJG5s4uH2aRKGGPGSGWrLJHXrlicVEcgr+CVvzhhC