"failed to install" going from 11.6.0 HF4 to 11.6.5.3

Hello,

I was upgrading an F5 from 11.6.0 HF4 to 11.6.5.3 into a partition that previously held code version 11.2.something. I got a "Failed to Install" message on th GUI and the contents of the liveinstall log show a return code of 9;

*** Live install start at 2021/07/17 10:18:06 ***

info: Daemon-driven execution indicated by ENV variable.

info: Repository tm_install version/release is 2.8.8.2/7.0

info: System tm_install version/release is 2.8.7/480.0

info: Updating system tm_install files from /shared/images/BIGIP-11.6.5.3-0.0.2.iso

................................................................................

7518 blocks

info: Installer on image is newer, reexec

info: Daemon-driven execution indicated by ENV variable.

info: Running updated installer.

info: Platform id is C113

info: Basic disk format validation passed.

01020036:3: The requested database variable (config.encryption) was not found.

info: System already has perl-RPM2

info: Selected product requires a minimum of 1024 MiB of ram.

info: License entitlement check; pvd = 20140805, scd = 20171003

info: Begin Install: BIG-IP 11.6.5.3 build 0.0.2 from /shared/images/BIGIP-11.6.5.3-0.0.2.iso to sda, 1

info: Updating maintenance OS.

progress: 0/100

info: No MOS update necessary; system has 2.8.8.2 - 7.0, media has 2.8.8.2 - 7.0

progress: 4/100

info: setting ownership of sda as mixed

progress: 6/100

info: Creating target filesystems.

info: Installing packages.

error: Installation process lock held by running process 838.

info: capture: status 0 returned by command: cat /proc/838/status

info: >++++ result:

info: Name:image2disk

info: State:S (sleeping)

info: Tgid:838

info: Pid:838

info: PPid:1

info: TracerPid:0

info: Uid:0000

info: Gid:0000

info: Utrace:0

info: FDSize:64

info: Groups:

info: VmPeak:  62084 kB

info: VmSize:  51828 kB

info: VmLck:      0 kB

info: VmHWM:  54500 kB

info: VmRSS:  46192 kB

info: VmData:  43052 kB

info: VmStk:    112 kB

info: VmExe:     12 kB

info: VmLib:   8356 kB

info: VmPTE:    136 kB

info: VmSwap:      0 kB

info: Threads:1

info: SigQ:0/128561

info: SigPnd:0000000000000000

info: ShdPnd:0000000000000000

info: SigBlk:0000000000000000

info: SigIgn:0000000000001084

info: SigCgt:0000000180004003

info: CapInh:0000000000000000

info: CapPrm:fffffffffffffeff

info: CapEff:fffffffffffffeff

info: CapBnd:fffffffffffffeff

info: Cpus_allowed:aa

info: Cpus_allowed_list:1,3,5,7

info: Mems_allowed:00000000,00000001

info: Mems_allowed_list:0

info: voluntary_ctxt_switches:4503

info: nonvoluntary_ctxt_switches:5625

info: >----

info: capture: status 0 returned by command: cat /proc/838/cmdline

info: >++++ result:

info: /usr/bin/perlinfo: >----

Terminal error: Failed to install.

*** Live install end at 2021/07/17 10:18:39: failed (return code 9) ***

Retrying the installation eventually worked. Does anyone have any ideas on what caused the initial failure? I may have double-clicked on the Install button as it didn't seem to be going anywhere. Would that cause the observed failure?

Kind Regards

Cathy