Strange freeze issue

Hello!
I have the following problem: I want to run a Logic Nodes Entrypoint via Javascript, which works just fine. However, in this particluar project I'm working on, there seems to be this issue: Whenever I use Show/Hide or Delay nodes (and probably also others), it'll only work once. I press the button, the entrypoint gets runned, fine. I press it again - the web application suddenly freezes! The console says:

TypeError: callstack[(callstack.length - 1)].logic_func is null
TypeError: null has no properties

So far I haven't found anything on that message. Does somebody have a clue what could be going on there?

Just tested it on a fresh project and it seems to be exactly the same issue. I've attached the project files here. The HTML button is supposed to show the cube, trigger an animation and hide it again. It does so once, but when you click it a second time, it freezes.

testing.zip

Hello!
This is definitely a bug. Thanks for the report. Will work on it.

Thank you very much! I hope this will be fixed asap.

Here is a fix for this bug.

we managed to apply the patch, but to no effect, because b4w.js and b4w.min.js are used at runtime.

can you upload a patched version of these files or tell us how to build them?

Currently to build engine you need *nix environment (bash, make). It is native for Linux or OSX, but for Windows you have to use for some software which implements this environment, e.g. Cygwin.
The build command is:

make compile_b4w

Currently to make all modifications to be applied you can update your app to use es6 modules. See simple_app project from SDK. There is two versions which you can compare and understand how to update your app.
Anyway, I've rebuilt the engine for you. See the attachment.

awesome! thank you for the quick reply!