The task 'Complete importing of public folder with id' fails with the following error message:
Exception during execution of MPF request: 'Unspecified error '.
There are sub-folders named IPM_SUBTREE in the customer's Public Folder and the Exchange Management Shell command like:
get-publicfolder -Identity "\P001021269\SII\IPM_SUBTREE" | get-publicfolderclientpermission
fails for such folder with the error like:
Get-PublicFolderClientPermission : There is no existing public folder which matches the identity '000000001A447390AA6611CD9BC800AA002FC45A03001B5343E1C41E8F459A57C9C81F5DBE1B034EF6F5F80C0000'. At line:1 char:93 + get-publicfolder -Identity "\P001021269\SII\IPM_SUBTREE" | get-publicfolderclientpermission <<<<
Task may fail because of wrong permissions set on folders named IPM_SUBTREE. Such folders are created during import/export of folders into/from Exchange through Outlook or other program.
'IPM_SUBTREE' folders are not necessary to keep after folders (non-IPM_SUBTREE ones) have been imported into Exchange. Thus they can just be removed. The task should be restarted then.