GSON Parse error when opening diagram

[petervdonovan]

I did not observe any effects from the GUI, but this error message appeared in the output (View -> Output -> LF Language Server):

May 18, 2022 1:52:26 PM org.eclipse.lsp4j.jsonrpc.RemoteEndpoint logIssues
WARNING: Issue found in NotificationMessage: Message could not be parsed.
com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected a string but was BEGIN_ARRAY at line 1 column 56 path $.params
	at com.google.gson.Gson.fromJson(Gson.java:975)
	at org.eclipse.lsp4j.jsonrpc.json.adapters.MessageTypeAdapter.fromJson(MessageTypeAdapter.java:329)
	at org.eclipse.lsp4j.jsonrpc.json.adapters.MessageTypeAdapter.parseParams(MessageTypeAdapter.java:249)
	at org.eclipse.lsp4j.jsonrpc.json.adapters.MessageTypeAdapter.read(MessageTypeAdapter.java:119)
	at org.eclipse.lsp4j.jsonrpc.json.adapters.MessageTypeAdapter.read(MessageTypeAdapter.java:55)
	at com.google.gson.Gson.fromJson(Gson.java:963)
	at org.eclipse.lsp4j.jsonrpc.json.MessageJsonHandler.parseMessage(MessageJsonHandler.java:119)
	at org.eclipse.lsp4j.jsonrpc.json.MessageJsonHandler.parseMessage(MessageJsonHandler.java:114)
	at org.eclipse.lsp4j.jsonrpc.json.StreamMessageProducer.handleMessage(StreamMessageProducer.java:193)
	at org.eclipse.lsp4j.jsonrpc.json.StreamMessageProducer.listen(StreamMessageProducer.java:94)
	at org.eclipse.lsp4j.jsonrpc.json.ConcurrentMessageProcessor.run(ConcurrentMessageProcessor.java:113)
	at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:539)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
	at java.base/java.lang.Thread.run(Thread.java:833)
Caused by: java.lang.IllegalStateException: Expected a string but was BEGIN_ARRAY at line 1 column 56 path $.params
	at com.google.gson.stream.JsonReader.nextString(JsonReader.java:824)
	at com.google.gson.internal.bind.TypeAdapters$15.read(TypeAdapters.java:380)
	at com.google.gson.internal.bind.TypeAdapters$15.read(TypeAdapters.java:368)
	at com.google.gson.Gson.fromJson(Gson.java:963)
	... 15 more

This error can be reproduced by opening lingua-franca/test/C/src/ArrayFree.lf and opening the corresponding diagram.