This is a known issue and the PCR PEP0299618R has been created for that.
This issue should be fixed in VJD V6.2 SP4.1
Pending the fix, please restore system operating system to the SD card with the backup/Restore tool and the OS image. After that, insert the SD card back to the HMI unit when it is turned off. Then power the unit back on, the operating system should be restored automatically from the SD card. Please refer the attached file for an example.