I have isolated the problem. The issue was with dynamic memory allocation on our test server. This was definitely a localized issue.
Cheers

@Danp thanks for replying.
I do the standard update as per the wiki.

$ git pull --ff-only
$ yarn
$ yarn build

Cheers

I've restored from a snapshot and rebuilt. Now the build process finished and everything seems to be working, but i did get following errors during the build:

Segmentation fault
/usr/bin/env: error while loading shared libraries: libc.so.6: cannot map zero-fill pages
Segmentation fault
error Command failed with exit code 127.
error Command failed with exit code 139.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
error Command failed with exit code 139.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

and

when the build finished i got this:

Successfully compiled 127 files with Babel.
[15:43:40] Finished 'buildScripts' after 3.12 min
[15:43:40] Finished 'build' after 3.12 min
✖ 4
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

Thanks for any insight..

Hi,
I am building from source. I have xo-server 5.50.1 and xo-web 5.50.3 installed. I am getting the following error, any guidance would be appreciated.
Thanks

[15:17:49] 'buildScripts' errored after 2.02 min
[15:17:49] Error: Cannot find module '@xen-orchestra/template' from '/opt/xen-orchestra/packages/xo-web/src/xo-app/new-vm'
    at /opt/xen-orchestra/node_modules/browser-resolve/node_modules/resolve/lib/async.js:46:17
    at process (/opt/xen-orchestra/node_modules/browser-resolve/node_modules/resolve/lib/async.js:173:43)
    at ondir (/opt/xen-orchestra/node_modules/browser-resolve/node_modules/resolve/lib/async.js:188:17)
    at load (/opt/xen-orchestra/node_modules/browser-resolve/node_modules/resolve/lib/async.js:69:43)
    at onex (/opt/xen-orchestra/node_modules/browser-resolve/node_modules/resolve/lib/async.js:92:31)
    at /opt/xen-orchestra/node_modules/browser-resolve/node_modules/resolve/lib/async.js:22:47
    at FSReqWrap.oncomplete (fs.js:152:21)
[15:17:49] 'build' errored after 2.02 min

Thank you for clarifying. Just didn't want to bang my head against the wall trying to make it work if its not there in a first place.
Cheers!

Just to clarify, in Community Version all registration options are greyed out for me. Am i doing something wrong?

Thank you @olivierlambert
Is it possible to register a community version? I cant seem to find a way to do this anywhere?
Cheers

Hi, sorry if I missed something obvious. With the latest update i can now see the Hub tab in the UI however there are no templates available there. What can I do to be able to access the templates?
Thanks

In case someone ran into the same problem here is how I solved it.
I had a feeling this was http mounts issue. I checked and looks like during update process the .xo-server.toml got deleted. I copied the sample one from the /opt/xen-orchestra/packages/xo-server/sample.config.toml , edited the http.mount and bob's your uncle.

I have a feeling this has something to do with the format of that file change. When I originally built from source the file has a slightly different syntax and it was called .xo-server.yaml. At least according tot he directions I used to build. In any case its all back to normal now.
Thanks you everyone for your help.