Comment # 19 on bug 1047852 from Dave Plater

(In reply to Felix Miata from comment #18)
> Still happening with libjack0-1.9.12-lp151.3.3.1, possibly taking a bit
> longer to manifest. From .xsession-errors:
> 1571166625338	addons.update-checker	WARN	onUpdateCheckComplete failed to
> parse update manifest: [Exception... "Update manifest is missing a required
> addons property."  nsresult: "0x80004005 (NS_ERROR_FAILURE)"  location: "JS
> frame :: resource://gre/modules/addons/AddonUpdateChecker.jsm ::
> getRequiredProperty :: line 473"  data: no] Stack trace:
> getRequiredProperty()@resource://gre/modules/addons/AddonUpdateChecker.jsm:
> 473 <
> parseJSONManifest()@resource://gre/modules/addons/AddonUpdateChecker.jsm:483
> <
> UpdateParser.prototype.onLoad/parser()@resource://gre/modules/addons/
> AddonUpdateChecker.jsm:655 <
> UpdateParser.prototype.onLoad()@resource://gre/modules/addons/
> AddonUpdateChecker.jsm:675 <
> UpdateParser/<()@resource://gre/modules/addons/AddonUpdateChecker.jsm:593 <
> onStopRequest()@resource://gre/modules/WebRequest.jsm:347
> jack_client_new: deprecated
> Cannot connect to server socket err = No such file or directory
> Cannot connect to server request channel
> jack server is not running or cannot be started
> JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping
> unlock
> JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping
> unlock

This is standard if jackd cannot be started or reached for some reason.
See:
http://jack-audio.10948.n7.nabble.com/Jack-Devel-Jack-will-not-start-td19777.html
cutting repeated sections .....

> akode: Guessed format: xiph
> X Error: BadWindow (invalid Window parameter) 3
>   Major opcode:  19
>   Minor opcode:  0
>   Resource id:  0x3800b46
> KNotify::playTimeout
> jack_client_new: deprecated
> Cannot connect to server socket err = No such file or directory
> Cannot connect to server request channel
> jack server is not running or cannot be started
> JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping
> unlock
> JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping
> unlock
> akode: Guessed format: xiph
> KNotify::playTimeout
> KCrash: Application 'knotify' crashing...
> X Error: BadWindow (invalid Window parameter) 3
>   Major opcode:  19
>   Minor opcode:  0
>   Resource id:  0x3800bbf
> X Error: BadWindow (invalid Window parameter) 3
>   Major opcode:  20
>   Minor opcode:  0
>   Resource id:  0x2e0000b
> X Error: BadWindow (invalid Window parameter) 3
>   Major opcode:  20
>   Minor opcode:  0
>   Resource id:  0x2e0000b
> X Error: BadWindow (invalid Window parameter) 3
>   Major opcode:  19
>   Minor opcode:  0
>   Resource id:  0x2e0000b

knotify has crashed apparently trying to start jackd
I've looked for a phonon jack to run jack as a backend in kf5 but it doesn't
appear to exist. In the days when I used kde3 I tried the jack audio backend
with no success. Is jack the only available backend for kde3?