Geometry parts missing in HTML5 build

We created an interactive Application with Unreal for Product Presentation. It includes a 360° view and animations to demonstrate different functions of the Product,enableable by clicking on parts.
It’s made mainly with Blueprints.
We’re able to Build the Application for Windows, and it works fine.
Some Parts of the Product are high detailed and contain a lot of Polygons.
There are some Error Messages in the Output Log when we build the Application, but it still works.

Now we want to build the same Application for HTML5 web use, but there’s multiple problems we came across:

If we build the whole thing with functions and animations, and we start it in a Browser (Firefox in this case) we get the Error Message: Script error.

If we just load the geometry into an empty scene, without animations, the application starts and we can view the object, but some of the geometry is missing.

So the questions now are:

  • Is there a limit for the Size of an HTML5 Application?
  • What kind of settings do we have to pay attention to for a HTML5 build? → We already changed the Build Configuration to Shipping and disabled Use Pak File.

Thanks for your answers and please tell if you need more information to solve this issue!