[DUPLICATE] Cannot backup to FTP location due to errors 41, 46 and 20

We have been trying to backup to FTP with our trial of Acronis 11.5 Backup and Recovery. We are receiving the following errors.

We know it's not an issue with credentials because we have input the same ones into Filezilla and Windows and are able to fully access the location without any limitations.

Strangely it must be able to access the location as it stores a .xml file for the backup job.

Any help would be hugely appreciated.

ProtectCommand: Failed to execute the command.
Additional info:
--------------------
Error code: 41
Module: 307
LineInfo: e6792a5ee190dda7
Fields: $module : agent_protection_addon_vs_37687
Message: ProtectCommand: Failed to execute the command.
--------------------
Error code: 46
Module: 64
LineInfo: 91e4c52610c9194
Fields: path : ftp://u36653.your-backup.de/AcronisBackup/, $module : disk_bundle_vs_37687
Message: Failed to open the backup location.
--------------------
Error code: 20
Module: 4
LineInfo: 31813f5926d10e2e
Fields: $module : disk_bundle_vs_37687
Message: Access to the file is denied.
--------------------

This is a duplicate of this thread.