Clean install of Ubooquity on UnRaid 6.8.1 does not progress beyong "Loading preferences" ...

I had this running and moved onto including my Calibre library. It required many, many restarts to complete the scanning of the Calibre library I even upped the MAXMEM in between. I could see the Calibre library occasionally, but not consistently. Now I see the log files show, after starting Ubooquity, doesn't progress beyond "Loading preferences" - see below. I removed the Docker container and installed again from scratch but get the same results. I have deleted the preferences.json file and restarted but same ...

[s6-init] making user provided files available at /var/run/s6/etc...exited 0.
[s6-init] ensuring user provided files have correct perms...exited 0.
[fix-attrs.d] applying ownership & permissions fixes...
[fix-attrs.d] done.
[cont-init.d] executing container initialization scripts...
[cont-init.d] 01-envfile: executing...
[cont-init.d] 01-envfile: exited 0.
[cont-init.d] 10-adduser: executing...

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GID/UID
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User uid: 99
User gid: 100
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[cont-init.d] 10-adduser: exited 0.
[cont-init.d] 30-config: executing...
[cont-init.d] 30-config: exited 0.
[cont-init.d] 99-custom-files: executing...
[custom-init] no custom files found exiting...
[cont-init.d] 99-custom-files: exited 0.
[cont-init.d] done.
[services.d] starting services
[services.d] done.
[cont-init.d] 30-config: exited 0.
[cont-init.d] 99-custom-files: executing...
[custom-init] no custom files found exiting...
[cont-init.d] 99-custom-files: exited 0.
[cont-init.d] done.
[services.d] starting services
[services.d] done.
20200719 07:36:51 [main] INFO com.ubooquity.Ubooquity - Running with the following parameters - headless: true, libraryport: -1, adminport: -1, remoteadmin: true, host: 0.0.0.0, debug: false, execdir: /config
20200719 07:36:51 [main] INFO com.ubooquity.Ubooquity - #############################
20200719 07:36:51 [main] INFO com.ubooquity.Ubooquity - # Starting Ubooquity #
20200719 07:36:51 [main] INFO com.ubooquity.Ubooquity - #############################
20200719 07:36:51 [main] INFO com.ubooquity.Ubooquity - Java version: 1.8.0_242
20200719 07:36:51 [main] INFO com.ubooquity.Ubooquity - Java vendor: IcedTea
20200719 07:36:51 [main] INFO com.ubooquity.Ubooquity - java vm name: OpenJDK 64-Bit Server VM
20200719 07:36:51 [main] INFO com.ubooquity.Ubooquity - java runtime name: OpenJDK Runtime Environment
20200719 07:36:51 [main] INFO com.ubooquity.Ubooquity - Max heap size available: 966 MB
20200719 07:36:51 [main] INFO com.ubooquity.Ubooquity - OS name: Linux
20200719 07:36:51 [main] INFO com.ubooquity.Ubooquity - OS version: 4.19.94-Unraid
20200719 07:36:51 [main] INFO com.ubooquity.Ubooquity - OS architecture: amd64
20200719 07:36:51 [main] INFO com.ubooquity.Ubooquity - Loading local version info
20200719 07:36:51 [main] INFO com.ubooquity.Ubooquity - Ubooquity 2.1.2 built on 2018-10-14 at 12:58
20200719 07:36:51 [main] INFO com.ubooquity.Ubooquity - Creating application folders
20200719 07:36:51 [main] INFO com.ubooquity.Ubooquity - Loading preferences