Multiple serious plugin problems and with playlists.
A problem I thought was project-specific isn't project-specific after all :(
I have multiple problems that all appeared at the same time, after getting MIDI going in Ardour. I don't know that getting MIDI running caused the problems; I also did an apt-get update/upgrade that brought in newer versions of Calf plugins which does not preceed the first occurance of the problems but does seem to be involved in some way.
First: on loading many projects, I get a nontrivial pause, during which time disc space is shown to be 0h 0m 0s remaining, and the title bar project name alternates between askterisked and non-askterisked. This cycle of asterisk/non-asterisk appears to repeat the same number of times as I have Calf plugins plugged in across all tracks. So if I have an assortment of tracks N and a total of 10 Calf plugins across all tracks, it will cycle 10 times.
Pulling all the Calf plugins and plugging them back in again (same places, same setting) with LV2 versions makes this problem go away.
ALSO: projects with tracks with Calf (LADSPA) plugins don't play, and LADSPA Calf plugins seem to be misbehaving; I get anywhere from muted to noise to distorted play. Replacing them with LV2 Calf plugins (I think - the ones not marked LADSPA) makes this go away as well. (Note: I have two copies of most of the Calf plugins (and have for some time - honestly I don't know why, but the old ones go back to Ardour 2), some with (LADSPA) after the name, some without.)
Swapping plugins out is a bigger project than it may seem, because I have never, ever had presets load for me, despite having the subscriber version of Ardour. Checking the store, I see that the presets are _saved_, but they don't get loaded. I don't know why.
Now, once I do this, and have things playing and sounding right again, and no delay at startup, in these projects, I have very slow response to the record button (1.5ish seconds) and swapping playlists on tracks while playing results in that track going silent for 1.5ish seconds, and then resuming play, _delayed from the rest of playback_ by the _same amount of time_.
To wit: https://dl.dropboxusercontent.com/u/48493064/playlist-changing-delay.mov
That video quality is pretty weak; I can record it again with a desktop video recorder. But since Ardour is running output through my external interface and everything else uses the built-in motherboard sound, it wouldn't be as useful for this case, because of no sound.
When playing that video, note the fiddler dropping out for about a second and a half, while the other playback continues; then the fiddle comes back in, picking up immediately where it left off, delayed from the rest. I did it twice; the fallback is cumulative.
On projects not (...yet...) affected, and until a couple of weeks ago, I could change playlists more or less instantly; I would do this to audition phrases and the like during comping.
This collection of problems has rather kicked my workflow and progress on my current projects in the knees, so ... anybody? Help?