Release Notes GWT 2.6.0: "The ie6 permutation (which also handles IE 7) is now disabled by default. Support for IE6 and IE7 will be removed in the next major GWT release." Official relase Notes: http://www.gwtproject.org/release-notes.html#Release_Notes_2_6_0
By default IE6 permutation is disabled. But how I can enable the ie6 permutation to make my application work with ie6 and ie7?
Secound question: is the module.xml file the only way to enable the permuation. What's about a flag for the gwt compiler?
You can enable ie6 permutation with in your module descriptor by adding this line of code:
<extend-property name="user.agent" values="ie6" />
I thought we had it documented somewhere but anyway, just add this to your gwt.xml:
<extend-property name="user.agent" value="ie6" />
来源：https://stackoverflow.com/questions/21876765/gwt-2-6-0-how-to-enable-internet-explorer-6-7-permutation