How to fix if Debian cannot enter the graphical interface?

If Debian cannot enter the graphical interface, it may be due to the following reasons:

1. Graphics card driver issue: Make sure your graphics card driver is correctly installed and compatible with the system. You can try updating or reinstalling the graphics card driver.
2. Issue with X server: If the X server encounters a problem, it may result in the inability to access the graphical interface. You can try restarting the X server or reconfiguring it.
3. Configuration file issue: check and ensure that the configuration files related to the graphical interface are free of errors or corruption. You can try resetting or restoring the default configuration files.
4. Monitor issue: Verify that your monitor is functioning properly, connected correctly, and supporting the required resolution and refresh rate.
5. Other issues: If the above solutions do not work, there may be other problems such as hardware failures or other errors in the operating system. You can try reinstalling the operating system or contact technical support for assistance.

Before addressing this issue, it is recommended to back up important data to prevent loss.