Vaadin error: Failed to load the bootstrap javascript

I have a problem when I put one in software production made in vaadin constant mind I get this error.

Failed to load the bootstrap javascript: ./VAADIN/vaadinBootstrap.js?v=7.6.3 I have the software running in apache tomcat 8.0.30, on a server with ubuntu linux. that get this error and how to fix it? someone knows.


Please check the following post and try what’s suggested there (if you haven’t done so already):!/thread/2438273

I already check this thread, and none of these solutions work me. comiensa encuando the problem appears to me the following error

Comunication problem Take note of any unsaved data, and click here or press ESC to continue.
invalid JSON from server: 8387 |for (;;);[{"syncld":7, "changes" :[["change",{"pid":"0"},["0",

It happens after that error does not let me to application and get the error to comment.

this happens because I do not see what the error.