Ok, then it's no other way to help, I think. SEUS doesn't alter filesystem, rather it just updates main firmware. So grab PhoneXS++V12 and newest firmware from topsony.com's download or anywhere else.

Run PhoneXS, start connection, fill in MAIN and FS firmware fields, check Customise and run... it can take from a dozen minutes to a 4-5 hours, dependent on your luck.