You may notice after upgrading LMU to version 6.3.0 that it is unable to load the Exchange database into the Mail Restore (MR) application as it is referencing an invalid mountpoint path. The MR is looking for a path that is missing the "LMU_" prefix to the mountpoints folder (mounted by LMU) located under the C:\ProgramData\AppRecovery\MountPoints\ path.
If you have any questions or need assistance with a patch, please contact Support via Chat or by Service Request.
In case you are unable to apply the patch, the workaround requires manually mapping to the mountpoint path where the Exchange .edb, log, and system paths are located in the Mail Restore application (whether the mountpoint is mounted via the core or LMU).
Once the mountpoint paths are verified to be correct, you may open the Exchange database in MR to perform the mail restore.