If you access an NVR and receive an message displayed at the top of the main window, please check and confirm what the notification is advising.
If the notification is as shown in the image below then a 'File System Check' will need to be performed on the relevant hard disk drive listed in the advisory notification.
To perform a 'File System Check' follow the guide here.
Before performing a file system check ensure your NVR Touch is running firmware 1.0.48 #2399 or above.
If performing a file system check does not remove the HDD error warning message this means the HDD's data is corrupt and will require a format. The next step will be to backup a copy of any required video footage and additional data from the specific HDD show in the error message and then format that specific HDD. This will clear all error messages related to that HDD.