The error in your screenshot points to a Secure Boot / MOK issue rather than a partitioning problem.
You were able to reach the partitioning stage previously, which means the installer itself was capable of booting at least once. The failure now occurs before the installer starts.
The key message is:
Failed to open \\EFI\\BOOT\\mmx64.efi
Failed to start MokManager
MokManager (mmx64.efi) is used by shim when Secure Boot needs to process a pending key enrollment request. If that request exists in UEFI NVRAM but the boot media does not contain the required mmx64.efi file, boot can fail exactly as shown.
A few questions:
- Which Linux distribution are you installing?
- Is Secure Boot currently enabled?
- Did the installer previously ask you to create a Secure Boot password or enroll a key?
- Which tool was used to create the USB (Rufus, Ventoy, Balena Etcher, Fedora Media Writer, etc.)?
I would first try disabling Secure Boot temporarily, recreating the USB from a freshly verified ISO, and then booting again.
Based on the error shown, this looks more like a Secure Boot / MOK state problem than a disk partitioning problem.