[OnePlus 8T ROMs, Kernels, Recoveries, & Other Deve] fenice2:
Hi everyone

I thought I'd install a new ROM on my 8T and after using an 'unofficial' build of Evolution X this one seemed to be the obvious choice. :)

OK, first the warning - I'm no expert at flashing ROMs but I'm keen.

The first thing I did was update to the latest OnePlus firmware with these instructions:

https://wiki.lineageos.org/devices/kebab/fw_update - that worked but I noticed that the files to flash were fewer than those extracted from the payload.bin file, can you confirm if that's correct?

After that I tried flashing this ROM from the instructions in the first post and saw the following errors:

C:\Downloads\Evolution-X Fastboot ROMinstaller\fastboot_installer>ROMinstaller.bat
++
=================== ++++++
= ==== ++
= ==
= == =
= == =
= == =
= == =
= == =
= ====== =
========================
#########################################
##### Evo X Installer For OnePlus8T #####
#########################################
#########################################
####### By @thznutz87_xda telegram ######
#########################################
Do you want to install ROM ( Reccomended )[Y/N]?y
Sending 'recovery' (98304 KB) OKAY [ 2.375s]
Writing 'recovery' OKAY [ 0.344s]
Finished. Total time: 3.031s
Sending 'boot_a' (98304 KB) OKAY [ 2.375s]
Writing 'boot_a' OKAY [ 0.328s]
Finished. Total time: 3.031s
Sending 'dtbo' (24576 KB) OKAY [ 0.594s]
Writing 'dtbo' OKAY [ 0.063s]
Finished. Total time: 0.766s
Rebooting into fastboot OKAY [ 0.016s]

< waiting for any device >
fastboot: error: Failed to boot into userspace fastboot; one or more components might be unbootable.
< waiting for any device >
Resizing 'odm_a' OKAY [ 0.011s]
Sending 'odm_a' (1276 KB) OKAY [ 0.030s]
Writing 'odm_a' OKAY [ 0.101s]
Finished. Total time: 0.229s
Invalid sparse file format at header magic
Resizing 'system_a' OKAY [ 0.000s]
Sending sparse 'system_a' 1/4 (262096 KB) OKAY [ 6.875s]
Writing 'system_a' OKAY [ 0.516s]
Sending sparse 'system_a' 2/4 (262112 KB) OKAY [ 6.813s]
Writing 'system_a' OKAY [ 0.469s]
Sending sparse 'system_a' 3/4 (256368 KB) OKAY [ 7.344s]
Writing 'system_a' OKAY [ 0.485s]
Sending sparse 'system_a' 4/4 (254632 KB) OKAY [ 6.766s]
Writing 'system_a' OKAY [ 0.484s]
Finished. Total time: 38.868s
Invalid sparse file format at header magic
Resizing 'system_ext_a' OKAY [ 0.000s]
Sending sparse 'system_ext_a' 1/2 (262109 KB) OKAY [ 6.859s]
Writing 'system_ext_a' OKAY [ 0.516s]
Sending sparse 'system_ext_a' 2/2 (82679 KB) OKAY [ 2.391s]
Writing 'system_ext_a' OKAY [ 0.203s]
Finished. Total time: 12.703s
Invalid sparse file format at header magic
Resizing 'product_a' FAILED (remote: 'Not enough space to resize partition')
fastboot: error: Command failed
Sending 'vbmeta_a' (8 KB) OKAY [ 0.000s]
Writing 'vbmeta_a' OKAY [ 0.000s]
Finished. Total time: 0.047s
Sending 'vbmeta_system_a' (4 KB) OKAY [ 0.000s]
Writing 'vbmeta_system_a' OKAY [ 0.016s]
Finished. Total time: 0.047s
Invalid sparse file format at header magic
Resizing 'vendor_a' OKAY [ 0.016s]
Sending sparse 'vendor_a' 1/4 (256946 KB) OKAY [ 7.031s]
Writing 'vendor_a' OKAY [ 0.516s]
Sending sparse 'vendor_a' 2/4 (261208 KB) OKAY [ 6.812s]
Writing 'vendor_a' OKAY [ 0.453s]
Sending sparse 'vendor_a' 3/4 (261836 KB) OKAY [ 6.813s]
Writing 'vendor_a' OKAY [ 0.469s]
Sending sparse 'vendor_a' 4/4 (205544 KB) OKAY [ 5.344s]
Writing 'vendor_a' OKAY [ 0.391s]
Finished. Total time: 38.500s
FLASHING DONE.......
CLICK ENTER RECOVERY
WIPE DATA/FACTORY RESET
REBOOT SYSTEM
#########################################
# ONEPLUS LOVE! #
#########################################
ECHO is off.
Press any key to continue . . .
C:\Downloads\Evolution-X Fastboot ROMinstaller\fastboot_installer>

What causes this error: "Invalid sparse file format at header magic" - how do I fix this?

Many thanks in advance.