​You will have to do a manual format of the SD card.

Here are the steps to do so:

Please power of the device, retrieve the SD and insert it into a PC
1. Download the SD Card Tools
2. Open the SD Card Tools folder, find the folder SD Card Format Tool and run the SD formatter
3. Choose Drive- the volume label should be FHDRM
4. Press the Option button and choose Format Size Adjustment ON, press OK
5. Press Format.

6. Safe eject the SD
7. Insert back the SD into the unit
Here is the instructional video on how to do that https://smartwitness.freshdesk.com/support/solutions/articles/25000012273-format-sd