The error message about filesystem-extra.squashfs typically indicates that your ISO image is incomplete, which causes the extraction to fail during installation and ultimately leads to a system installation failure.

I'd recommend comparing the MD5 checksum of your local ISO file with the official one on the Deepin website to confirm they match. If the checksum is correct, the issue is most likely due to a faulty USB drive – try using a different USB stick (or re-burn the image to the same one with a tool like Ventoy), and the installation should proceed normally."