Error Messages and Resolution tips for XPlica Quick Migration Task
You may notice one or more of the error messages given below when using XPlica to connect to SharePoint and perform a migration. This is not an exhaustive compilation of all error messages, but an attempt to include as many known error messages and how to resolve the errors. Please refer Troubleshooting section of online help document for more information.
Error Message Resolution

The web application at "http://<<Url>>" could not be found. verify that you have typed the URL Correctly. If the URL Shuold be serving the existing content, the system administrator may need to add a new request URL mapping to intended the application.

The user account specified to perform migration does not having enough rights to perform the migration task. Please provide the credentials with the privileges specified in the related help file section.

Unable to connect XPlica Server Agent. Please ensure that XPlica Server Agent is running in the remote server with the specified port address.

Please make sure that the port you are using is configured in windows firewall in the target server and also ensure that the port and the server name you have mentioned to perform migration is correct.

Ensure the following:

1. The XPlica Server Agent is started in the remote server.
2. The Agent is running with the specified port.
3. The port which you are using to communicate with XPlica Server Agent from the client computer has been configured in the target server.

Logon failure: unknown user name or bad password.

Ensure that the account you are using to perform the migration task has sufficient privileges to store the ".DAT" files in the temp storage location.

 
Could not find Feature << Feature Name>> Ensure that all features available in the source site collection are also available and activated in the destination SharePoint site collection. If any feature is not installed in the destination, the migration import process will fail every time, until you install the required features.

(Or)

Choose the 'Fail Safe Settings' in XPlica Task Settings wizard step to continue migration without strictly checking the requirements in destination SharePoint.

Failed to compare two elements in the array.

In this case, the migration could not be started because the features used in the site collection are missing on the source server.

For e.g., If you activated a feature called "Bronze Colored Master page", but if the file "Feature.xml" for the above feature is missing in the source server, which means the migration cannot be started.

The file << library/folder1/folder11>> has been modified by (unknown) on <<Any Date and Time eg., 28 Nov 2011 09:43:16 +0300.>>

This error will cause the migration to fail. To avoid this problem, you can perform the migration process during off-peak hours.

 Object reference not set to an instance of an object.

The user account specified to perform migration does not have sufficient rights to perform the migration task. Please provide the credentials with the privileges specified in the related help file section.

<< <nativehr>  0x80070002 </nativehr> <nativestack> </nativestack> >> There is no Web named "<< werb relativa url>>". Ensure that the URL mentioned to connect to source and destination is correct and make sure that the credentials provided to connect to SharePoint have required privileges to perform migration.
The specified file or folder name is too long. The URL path for all files and folders must be 260 characters or less (and no more than 128 characters for any single file or folder name in the URL). Please type a shorter file or folder name. code: 0x800700ce XPlica Quick Migration task option does not support such long file path migration, as per the limit specified in the error message. Sometimes, the whole migration process may fail due to such long paths (or) the migration task will only ignore the long path files and continue with the rest of the migration.
Could not create content migration package.

Ensure that sufficient disk space is available in target SharePoint content database and the temp storage location. 

Error:The file "....\20120127-185639\ExportedFiles" does not exist. Ensure that the credential which you are using to connect destination does have enough rights to read and write contents in the temp storage location.
Access to the path '....\20120201-114756' is denied. Ensure that the credentials which you are using to connect source and destination SharePoint are having enough rights to read and write contents in the temp storage location.