Q:

I keep getting exceptions when I am trying to connect to the service

A:

Possible reasons:

You don't have the webServices section in the web.config file for the target solution.
You forgot to delete webServices section in the web.config in the source solution
Some assemblies dissappear from the target solution: SharpZipLib.dll, Sitecore.MigrationDAL.dll, nunit.framework.dll, etc

Q:

I get an error when I click the Next button

A:

If you get an error (something like this one: Backup or Autosave folder not found) before starting migration this means that the packager didn't install either the Backup or Autosave empty folders, which are required for migration. In order to fix it you shuld create whichever of these folders are missing, manually.

Q:

I get exceptions while migrating languages

A:

If you get an error while migrating languages one of the reasons for this problem is an incorrect ISO or regional code for this language. Have a look at your data and you should be attentive because ISO and Regional code are case-sensitive. To rectify this problem you can:

Modify the language item on the source solution and make appropriate changes in the databases (Note: we don't have autorename in Sitecore 4)
Make appropriate extended mapping in the MigrationConfig file

Q:

I can see the login rendering instead of site content Source: 4.3.2.13 Target: 5.X The login rendering is shown on the page instead of the rendering with content.

A:

The problem in Login Rendering functionality is that it was changed from Sitecore 4.3.2.13 onwards. In the Sitecore 4.3.2.13 login rendering is shown for the logged in users who have no access to the current item but Sitecore 5.X shows the login rendering for the Anonymous user. To resolve this problem you should just remove the value in the Login Rendering field for each xsl, web control and sublayout

Q:

There is a question mark in the language selector

A:

This means that you have migrated your language and data correctly but the language has an incorrect ISO-Regional code (as an example it may be in the wrong case). In order to fix this you should run a script in the master and web databases which will correct the language codes. Samples of the script can be found below:

update unversionedfields set [language]='nb-NO' where [language]='nb-no'

update versionedfields set [language]='nb-NO' where [language]='nb-no'

Q:

I get a System.Data.SqlClient.SqlException error in the log files. Source: any Target: Sitecore 5.3.x

A:

If you found System.Data.SqlClient.SqlException errors in the migration log with stack traces like this:

FATAL Unhandled exception while trying to transfering item '{XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}'
Exception: System.Data.SqlClient.SqlException
Message: A severe error occurred on the current command. The results, if any, should be discarded.
A severe error occurred on the current command. The results, if any, should be discarded.
Source: .Net SqlClient Data Provider
...
   at Sitecore.Data.SqlServer.SqlServerLinkDatabase.UpdateLinks(Item item, ItemLink[] links)
   at Sitecore.Links.LinkDatabase.UpdateReferences(Item item)
   at Sitecore.Links.ItemEventHandler.OnItemSaved(Object sender, EventArgs args)
   at Sitecore.Events.Event.EventSubscribers.RaiseEvent(String eventName, Object[] parameters, EventResult result)
   at Sitecore.Events.Event.EventSubscribers.RaiseEvent(String eventName, Object[] parameters)
   at Sitecore.Events.Event.RaiseEvent(String eventName, Object[] parameters)
   at Sitecore.Events.Event.RaiseItemSaved(Object sender, ItemSavedEventArgs args)
   at Sitecore.Events.Event.DataEngine_ItemSaved(Object sender, ExecutedEventArgs`1 e)

The solution: You forgot to disable the Event Handlers for the Link database in item:deleted and item:saved events. Look at the Pretransferring workflow.

Q:

On the live (source) site and target site I can see a different count of the menu, news, etc items and I am sure that the rendering is correct.

A:

If you run your target site on the master database it could be a problem with publishing functionality. Probably these items should not be published. You can either change the master database to web for your site or use the filterItems site attribute.