Please follow these steps:
1、 Enable the USB Flash Drive Debugging（I series NVR , later versions of v4.1.50）
2、 Copy the debug document to U-disk （ under the root directory ） on your
computer. The debug document is in attachment.
3、 Plug the U-disk to the rebooting NVR.
4、 Wait for NVR to reboot and remove the U-disk after the NVR reboots.
5、 Plug the U-disk to your computer , you can see two new files like
app_xxx.log bsp_xxx.log. You send the two files to me.
Note: this method is suitable for both I and E series NVR and the debug.cfg is the same for
both series .