[SOLVED] Zynaddsubfx GUI doesn't load [Ubuntu]

[farawayinspace]

Hello,
There was a massive update of Jack and lmms recently in the Ubuntu and Kxstudio repos. Now, I get some errors when loading Zyn. LMMS opens and operates okay, and the Zyn instruments produce sound. But when I try to load the Zyn GUI, it fails to load. The following symptoms:
- process RemoteZynAddSubFX hangs at 100%
- no Zyn GUI loads
- I can still play with LMMS after the Zyn GUI fails to load, but I think it eventually crashes, several minutes later.
- terminal output:
Error while writing.
Remote plugin did not connect.
Error while writing.
QProcess: Destroyed while process is still running.
ASSERT: "asize <= aalloc" in file /usr/include/qt4/QtCore/qvector.h, line 474
Aborted (core dumped)

And the following JACK messages just repeat x20-30 times...
07:51:26.940 XRUN callback (1).
Fri Sep 16 07:51:26 2016: ERROR: JackEngine::XRun: client = lmms was not finished, state = Running
Fri Sep 16 07:51:26 2016: ERROR: JackAudioDriver::ProcessGraphAsyncMaster: Process error

I am running UBuntu 16.06. Using LMMS 1.1.3-2kxstudio1. I can't tell which version of Zyn it is. I am using Jackd2 version 2:1.9.11~20160620-5~trusty1 from Universe.

[EDIT]: I upgraded from 14.04 to 16.04, with no change in symptoms.

[zonkmachine]

Hi!

There was a massive update of Jack and lmms recently in the Ubuntu and Kxstudio repos. Now, I get some errors when loading Zyn. LMMS opens and operates okay, and the Zyn instruments produce sound. But when I try to load the Zyn GUI, it fails to load.

This is a bit surprising actually. Not that it's starting to bug down now, but that it worked in the first place.
Do you use something other than xorg-server?
The trouble we've seen with zasfx gui is with the xorg-server in Ubuntu around 14.04 and is fixed by installing a later Ubuntu. 16.04 works.

Some related zasfx gui issue reports:
https://github.com/LMMS/lmms/issues/2100
https://github.com/LMMS/lmms/issues/2701
https://github.com/LMMS/lmms/issues/2811

[farawayinspace]

I just upgraded to 16.04, and the symptoms persist. I'm not sure whether it is an X, jack, Zyn, or lmms issue.

[farawayinspace]

Solved, based on the solution in viewtopic.php?f=7&t=1662
Both VSTs and Zyn GUI wouldn't load. Simple solution was to turn off "Sync VST plugins to host playback" in the LMMS settings. Weird that it would affect both VSTs and ZynAddSubFx, but there you go.

[Outer Mind]

Solved, based on the solution in viewtopic.php?f=7&t=1662
Both VSTs and Zyn GUI wouldn't load. Simple solution was to turn off "Sync VST plugins to host playback" in the LMMS settings. Weird that it would affect both VSTs and ZynAddSubFx, but there you go.

Oooh... This indeed works! I didn't think about that simple thing.