You can't use ng-if and ng-include in that way. Use this instead.
<div class='pianificazioneOpertion-module'>
<div class="container-fluid">
<div ng-if="step == false">
<ng-incude src="'pianificazioneModule/patrimonioNonFinanziarioModule/pianificazioneOperationModule/step.html'"></ng-include>
</div>
<div ng-if="step == true && operation.tipologia=='5'">
<ng-include src="'pianificazioneModule/patrimonioNonFinanziarioModule/pianificazioneOperationModule/venditaDonazione.html'"></ng-include>
</div>
</div>
</div>
This is because ng-include is a tag itself.
Check Angular docs for ngInclude https://code.angularjs.org/1.4.12/docs/api/ng/directive/ngInclude
UPDATE
Check this:
In addition, the browser's Same Origin Policy and Cross-Origin Resource Sharing (CORS) policy may further restrict whether the template is successfully loaded. For example, ngInclude won't work for cross-domain requests on all browsers and for file:// access on some browsers.
From Angular Docs. If you're trying to execute your code from file:// instead of http:// (running from node server, by example) it won't work because CORS policy may block it.
Run from Apache/nginx/Node Http server.
ng-include="'pianifi.... Thesrcattribute is only applicable on the<ng-include>element version of the directivesrcat ng-include?