Internal Server Error - Migration tool

Under Migration Tool | Export Tab | When you click on "Finish" tab after selecting the Target version, if you encounter the following error 

migratetool.global.sonicwall.com says "Internal Server Error".

This error is encountered if Bandwidth Management is enabled on the parent firewall which you will be exporting the configuration file from.

Under Firewall Settings | Bandwidth Management | Set the Bandwidth Management Type to "None". And then,  export the configuration file to be used in the migration tool.