Usage of Vaadin with F5 load balancer

Hi everyone! First of all thanks for reading!

I have a probably very specific question that might be very tricky to solve, but I don’t know what else to do.

I have a Vaadin site working fine on all browsers, but due to some customer requirements, it has to run also on a load balancer application with F5 technology. And here is where the problem appears.

When accesing the application through the load balancer, it works properly on Chrome and Mozilla Firefox but when running the application on IE 11 it doesn’t work at all. The error says something like this:

Tue Mar 22 11:33:09 GMT+100 2016 com.vaadin.client.ApplicationConfiguration SEVERE: (TypeError) : No se puede establecer la propiedad 'absoluteX' de referencia nula o sin (TypeError) : No se puede establecer la propiedad 'absoluteX' de referencia nula o sin definir at Unknown.F5_Inflate_index(eval code) at Unknown.Ptc(Unknown script code) at Unknown.Ycc(Unknown script code) at Unknown.Xcc(Unknown script code) at Unknown.Ucc(Unknown script code) at Unknown.Tcc(Unknown script code) Which basically says that the property “absoluteX” has null reference or it’s not defined. After some investigation, I guess it might be due to the javascript generation that Vaadin does on the “cache.js” file, cause this property appears two times in there.

What I did was to build an entirely new vaadin 7 project to see if the error keep appearing and it does, only that now is complaining about some other “alignment” property. This means the problem has to do purely with the sync of this F5 load balancer and Vaadin (nothing to do with my app).

So the question would be, does anyone know how to solve this or at least how to modify the bootstrap of this file so I can be sure this is the problem? (I’ve already tried by deleting everything on the header on the VaadinServlet with the modifyBootstrapPage() but it keeps generating that file).


Hi everyone!

I just find out that this is a versioning issue! I downgraded the vaadin version of this new project (made it following this guideline, to the 7.3.1 and now it’s working perfectly on IE 11 behind the load balancer!

I also somehow built a war with a newer version but with the CSS broken and it also worked (the CSS was not working, but the application itself did work). So I’m sure the problem comes from the CSS. New versions of Vaadin are generating some CSS that breaks IE when it’s behind this load balancer. What I still don’t understand is how is possible that these CSS properties that fail behind the load balancer are working accesing directly the application.

Could someone bring me some light into this?