fix up troubleshooting and known issues sections

Author: vkovec

com.unity.formats.fbx/Documentation~/knownissues.md

@@ -2,7 +2,7 @@
 
 * The FBX Exporter package does not support exporting `.asset` files.
 
-* Bind pose of animated skinned mesh is lost on export. For example, if you export an animated skinned mesh from Unity and import it into Autodesk® Maya® and Autodesk® Maya LT™ you will not be able to set the character into the bind pose using the **Rigging** > **Skin** > **Go to Bind Pose** command.
+* The bind poses of animated skinned meshes are lost on export. For example, if you export an animated skinned mesh from Unity and import it into Autodesk® Maya® and Autodesk® Maya LT™ you will not be able to set the character into the bind pose using the **Rigging** > **Skin** > **Go to Bind Pose** command.
 
 * Name or path changes are ignored when converting a Model instance
 

com.unity.formats.fbx/Documentation~/troubleshooting.md

@@ -1,19 +1,46 @@
 # Troubleshooting
 
-* When installing a new version of the FBX Exporter package after using version 1.3.0f1 or earlier, the link between Assets and FbxPrefab components may be lost. See [Updating from 1.3.0f1 or earlier](index#Repairs_1_3_0f_1) for repairing instructions.
+This section covers the following issues:
+    * [Upgrading the FBX Exporter from the Asset Store package](#AssetStoreToPackman)
+    * [Incorrect skinning on Animated Skinned Mesh](#SkinnedMeshExport)
+    * [Converting GameObjects with UI components](#ConvertUI)
+    * [Overwriting FBX files](#OverwritingFiles)
+    * [Tree primitive no longer editable after conversion](#EditableTree)
+    * [Trail and line particles lose material after being converted](#ParticlesLoseMaterial)
 
-* Animated skinned meshes may not export with the correct skinning if they are not in the bind pose on export (that is, not being previewed in the Animation or Timeline windows, and the original Rig's FBX must not contain animation)
+<a name="AssetStoreToPackman"></a>
+### Upgrading the FBX Exporter from the Asset Store package
 
-* For skinned meshes all bones must be descendants of the root bone. For example, if the root bone is "hips" and the right leg for the same skinned mesh is not a descendant of hips, export will fail.
+When installing a new version of the FBX Exporter package after using version 1.3.0f1 or earlier, the link between Assets and FbxPrefab components may be lost. See [Updating from 1.3.0f1 or earlier](index.md#Repairs_1_3_0f_1) for repairing instructions.
 
-* Converting hierarchies with UI components will break UI
-    * FIX: prepare hierarchy so that it has no UI elements before converting then add it back afterwards
-    
-* In some situations, when overwriting an FBX file on export. If the FBX file is used by an FBX Linked Prefab instance, it may lead to unexpected results such as additional objects added to the hierarchy.
-    * FIX: recommended not to overwrite an FBX unless certain that it is not used by a Prefab Variant
-    
-* Converting a Tree primitive makes the Tree no longer editable.
-    * FIX: make sure to only convert when finished editing the tree. Otherwise click undo after converting to return to previous state where tree was editable.
+<a name="SkinnedMeshExport"></a>
+### Incorrect skinning on Animated Skinned Mesh
+
+If animated skinned meshes do not export with the correct skinning, it may be because they are not in the bind pose on export.
+Before exporting the animated skinned mesh, check the following:
+* The skinned mesh animation is not being previewed in the Animation of Timeline windows, as this may cause issues on export
+* The original Rig's FBX does not contain animation
+    * It is currently not possible to fix this issue in Unity. Animation will first need to be separated from the Rig in a separate modeling software such as Autodesk® Maya®
+
+<a name="ConvertUI"></a>
+### Converting GameObjects with UI components
+
+Converting hierarchies with UI components (i.e. RectTransform) will break the UI.
+A workaround for this is to first prepare the hierarchy so that it has no GameObjects with UI elements before converting, then add the UI elements to the FBX Linked Prefab afterwards.
+
+<a name="OverwritingFiles"></a>
+### Overwriting FBX files
+
+In some situations, overwriting an FBX file that is used by an FBX Linked Prefab instance, may lead to unexpected results such as additional objects being added to the Prefab hierarchy.
+Therefore, we recommend not to overwrite an FBX file that is used by an FBX Linked Prefab.
 
-* Trail and line particles lose material after being converted
-    * FIX: re-apply the lost materials after converting
+<a name="EditableTree"></a>
+### Tree primitive no longer editable after conversion
+
+Converting a Tree primitive will make the Tree no longer editable.
+Make sure to only convert the Tree when finished editing. Otherwise click undo after converting to return to previous state where the Tree was editable.
+
+<a name="ParticlesLoseMaterial"></a>
+### Trail and line particles lose material after being converted
+
+If materials are lost when converting trail or line particles, the materials will currently need to be re-applied to the FBX Linked Prefab after conversion.