It's impossible to help you to fix this issue without a capx, try to make an example where this error appears, so we can see what's wrong with it. I test all of my projects with cocoonjs wifi preview, all of them works fine, so the problem is not cocoonjs. And i heard about problems with cocoonjs and tab devices, just update the cocoonjs launcher to latest version, and use 2.0.2 version of exporter, all problems with tabs and galaxys were fixed there.