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+# UPGRADE FROM 1.x to 2.0
+
+## Themes
+Themes are no longer part of EzCoreExtraBundle. 
+This feature has been extracted to [ezsystems/ezplatform-design-engine](https://github.com/ezsystems/ezplatform-design-engine).
+
+### Config migration
+#### Design declaration, fallback and selection for a SiteAccess
+
+> **Important**: For new configuration to work, you MUST install `ezsystems/ezplatform-design-engine`.
+
+**Before**
+```yaml
+ez_core_extra:
+    design:
+        list:
+            my_design: [theme1, theme2]
+            
+    system:
+        my_siteaccess:
+            design: my_design
+```
+
+**After**
+```yaml
+ezdesign:
+    design_list:
+        my_design: [theme1, theme2]
+
+ezpublish:
+    # ...
+    system:
+        my_siteaccess:
+            design: my_design
+```
+
+#### PHPStorm support
+**Before**
+```yaml
+ez_core_extra:
+    phpstorm:
+
+        # Activates PHPStorm support
+        enabled:              '%kernel.debug%'
+
+        # Path where to store PHPStorm configuration file for additional Twig namespaces (ide-twig.json).
+        twig_config_path:     '%kernel.root_dir%/..'
+```
+
+**After**
+```yaml
+ezdesign:
+    phpstorm:
+
+        # Activates PHPStorm support
+        enabled:              '%kernel.debug%'
+
+        # Path where to store PHPStorm configuration file for additional Twig namespaces (ide-twig.json).
+        twig_config_path:     '%kernel.root_dir%/..'
+```
+
+#### Additional template override paths
+
+**Before**
+```yaml
+ez_core_extra:
+    design:
+        override_paths:
+            - "%kernel.root_dir%/another_override_directory"
+            - "/some/other/directory"
+```
+
+**After**
+```yaml
+ezdesign:
+    template_override_paths:
+        - "%kernel.root_dir%/another_override_directory"
+        - "/some/other/directory"
+```
+
+#### Assets pre-resolution
+**Before**
+```yaml
+# ezplatform_prod.yml
+ez_core_extra:
+    # Force runtime resolution
+    # Default value is '%kernel.debug%'
+    disable_assets_pre_resolution: true
+```
+
+**After**
+```yaml
+# ezplatform_prod.yml
+ezdesign:
+    # Force runtime resolution
+    # Default value is '%kernel.debug%'
+    disable_assets_pre_resolution: true
+```