It pops up when I try the 1st option in the installation type

Traceback (most recent call last):
  File "/usr/lib/ubiquity/ubiquity/frontend/kde_ui.py", line 1072, in on_next_clicked
    self.dbfilter.ok_handler()
  File "/usr/lib/ubiquity/plugins/ubi-partman.py", line 3246, in ok_handler
    seen=False)
  File "/usr/lib/ubiquity/ubiquity/filteredcommand.py", line 367, in preseed_as_c
    self.preseed(name, self.translate_to_c(name, value), seen)
  File "/usr/lib/ubiquity/ubiquity/filteredcommand.py", line 337, in translate_to_c
    raise ValueError(value)
ValueError: Guided - resize SCSI1 (0,0,0), partition #7 (sda) and use freed space

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubiquity 18.04.14.12 [modified: lib/partman/automatically_partition/question]
ProcVersionSignature: Ubuntu 4.18.0-15.16~18.04.1-generic 4.18.20
Uname: Linux 4.18.0-15-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: amd64
CasperVersion: 1.394
CurrentDesktop: KDE
Date: Sat Mar 30 14:25:56 2019
InstallCmdLine: file=/cdrom/preseed/kubuntu.seed boot=casper maybe-ubiquity initrd=/casper/initrd quiet splash --- maybe-ubiquity
LiveMediaBuild: Kubuntu 18.04.2 LTS "Bionic Beaver" - Release amd64 (20190210)
SourcePackage: ubiquity
UpgradeStatus: No upgrade log present (probably fresh install)