If errors appear during scanning your shares, then these are listed during scanning.
Frequent errors are for example, too long path names. The path name is composed of the computer names and all directory names down to the lowest directory. The complete length must not exceed 260 characters.
An additional problem could be that despite administrator rights you have no access to a directory. (Only the legitimate owner has the rights, the administrator has none.) In that case, the error message “Access to ACL not permitted” appears.
There misconfigurations have to be removed before the migration.
In the project management, you find a red symbol for each project that has error messages. Use the symbol to show the messages in a list.
Once you have korrected all issues, click on “Rescan project” to scan the source again and continue with the project.