Error upon clicking start game in launcher

Check if the folder: Aki_Data\Launcher\Patches\aki-core\EscapeFromTarkov_Data\Managed

has a file in it called: Assembly-CSharp.dll.bpf

You could try extracting SPT again, make sure it extracts everything from the zip.

My gut feeling is its your anti-virus deleting files it thinks are bad. Let us know what you find.

It is necessary to remove the "read-only" check mark in the properties of the EFT folder and apply it to all folders and files in this folder.

so from discussion with the third party, AKI was being left separate, needed to follow the install guide.