RuntimeException: (JavaScript) TypeError: Cannot find function $putFloat in object null@2b1f4d63

[cyberquarks]

I managed to run a test for Google FlatBuffers, here: https://github.com/cyberquarks/flatbuffers-demo-teavm/blob/main/src/test/java/MyGame/Sample/FlatbuffersTest.java but it throws this error:

Running MyGame.Sample.FlatbuffersTest
Tests run: 3, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 7.694 sec <<< FAILURE!
testFlatBufferBuilder(MyGame.Sample.FlatbuffersTest)  Time elapsed: 3.998 sec  <<< ERROR!
java.lang.RuntimeException: java.lang.RuntimeException: (JavaScript) TypeError: Cannot find function $putFloat in object null@2b1f4d63.
    at <JS>.$rt_throw(test.js:173)
    at org.teavm.junit.TestEntryPoint.run(TestEntryPoint.java:34)
    at org.teavm.junit.TestEntryPoint.main(TestEntryPoint.java:44)
    at <JS>.<unknown_function>(test.js:458)
    at <JS>.$rt_startThread(test.js:7838)
    at <JS>.<unknown_function>(test.js:457)
    at <JS>.runMain(test.js:5)
    at org.teavm.junit.HtmlUnitRunStrategy.runTest(HtmlUnitRunStrategy.java:82)
    at org.teavm.junit.TestRunner.runImpl(TestRunner.java:90)
    at org.teavm.junit.TestRunner.lambda$run$2(TestRunner.java:85)
    at org.teavm.junit.TestRunner.lambda$init$0(TestRunner.java:51)
    at java.base/java.lang.Thread.run(Thread.java:834)
Results :
Tests in error: 
  testFlatBufferBuilder(MyGame.Sample.FlatbuffersTest): java.lang.RuntimeException: (JavaScript) TypeError: Cannot find function $putFloat in object null@2b1f4d63.
Tests run: 3, Failures: 0, Errors: 1, Skipped: 0

Anyone can give a hint?

ps. the complete runnable test is in the linked code

[ScraM-Team]

Cannot find function $putFloat in object null@2b1f4d63.

This seems like the TeaVM version of a null pointer exception -- It's trying to invoke a method on a null object.

How did you run this? Perhaps you can enable TeaVM debugging to get more information.

Also, if there is a way to make a smaller test case that could help narrow things down.