I have the same trouble, did you find a solution?
I have a Wago controller 750-880. I have created from the demo, another application.
I download it, and with my PC all is fine. I can log, download, check, change variables.
I also tested with Firefox, Opera and Google Chrome, the Web visualization. Everything is ok.
Now, I have a Web Panel, from SAIA, with CrE-ME Java virtual Machine v4.12.
I can start the Manager through the Internet explorer, and can see everything I need. It also ask me for the pass when entering in restricted pages, which I can enter with no problems.
The problem is the Web Visualization. It shows a "Loading..." text inside a gray square but nothing happens.
In the status bar said the Applet was started... but the Loading square is still there.
The CRE-Me software has the possibility to look into the applet only, but when it starts opening, it closes, and I can't see anything.
The CRE-Me has a demo applet, which I downloaded in the plc and works... I even looked for a java applet game, which I can play with no problems.
There is a problem with the java, and I don't have a clue how to start looking into that.
I started using CoDeSys 22.214.171.124, and upgraded to 126.96.36.199 with the same result.
If anybody has an idea what I can do, please post here or send me a pm.
Thanks to all for the help