[Steinway]

Just sat down at the piano to practice a bit.. Played the first 12 pages of Schumann's violin sonata, worked like a charm as always.
Turned to page 13, and was met with complete blackness. Help! Panic! Onwards to page 14, everything normal. Back to page 13: Black screen.
Tried jumping a bit back and forth in the score, all pages normal except page 13, which was always completely black.
Went back to the library screen, opened the score again. Everything normal, even page 13. I've played from the same file hundreds of times without seeing the black screen.

This has happened a few times before, with different files (only three times maybe, during the almost two years I've been using MS and MSP.) I haven't seen it for a long while, so I thought the problem was long gone, but here it was again..
Has anyone else reported this behavior lately? Luckily, this has never happened during a performance, but it makes me a bit reluctant (at least very scared) to use MSP in public until I know what's causing the problem, and how to avoid it..

Any help appreciated!

Samsung Note Pro, Android 5.0.2, MSP 1.3.6

[Skip]

Its happened to me quit awhile ago. If/when it happens again try pinching it smaller. You can also try unchecking settings>display settings>allow zoom out past 100%.

[Steinway]

Thanks!

But zoom-out beyond 100% is not enabled - and suddenly having to pinch-zoom in the middle of a performance isn't really an option (I would probably panic too much to think clearly if it happened, and either way need both hands for playing..). Still, if it happens again at home, I will try zooming to see if it helps.

Trying to reproduce the problem, no luck so far.. As far as I can recall, this has always happened when swiping the screen to turn, never when using the bluetooth pedals (which I would always use in a performance situation). But I may be wrong.

[Zubersoft]

Please keep me posted if you are able to reproduce the problem. There definitely should never be a situation where a page fails to render like that. I'm curious if you had advanced all the way to the start, then back to the problematic page if it would have displayed it at that point. I'll keep an eye out for this problem, but I can't say I've seen anything like that recently.

[Steinway]

I've have two more occurrences of this problem since my last post, with two different files. Still not able to reproduce it at will, but both these times I've touched the screen to turn the page (ie. I have not used my BT pedals). I'm not sure how much more helpful information I can add at this point, but at least I've tested what you asked for: going back to the first page and then back to the problematic page did not solve the problem (the page was still black) if turning a page at a time, but going back to the first page, and then skipping straight back to the problematic page (page 11 in this case) DID solve it. (or rather, eventually solved it, as the page at first tried to reload, but just showed the spinning circle forever - so I had to once more turn back to page 10, the back to 11 again, whereupon the page finally rendered correctly.
As I never seen this behiavor when using the pedals to turn, I still feel comparatively confident that it won't happen during performances. The only times I touch the screen to turn, is when I practice at home, and these are the only times I've seen the problem. Still, I'm a tad nervous about this, as I've now seen the black page three times in just a couple of weeks...

[Zubersoft]

Just for clarification, which page display mode are you using and in which tablet orientation? Is it happening while playing through a setlist or an individual song? I'm assuming all the songs are using PDFs, correct? About how long does it take for the average page to render?

One way for me to address this problem (which I don't really want to do), is to put a period check in (every second or two) that determines if a page isn't rendering for some reason and triggers it to render again. This reason I don't really want to do this is that the software should never get into a state where it doesn't have a render request for a given page and that page is also not being triggered to render by changing the page, so it just generates extra work that the software would be doing for no gain (which uses battery power). I need to find a reliable way to get the software in the state where a page is not rendering so I can figure out what went wrong, but due to the nature of the problem, I don't think I'm going to get that.

[Zubersoft]

After working on this for quite some time today, I think I've finally located the problem that can cause pages to stop being rendered. It happens most often in a setlist with a lot of songs using different PDFs (especially short songs with only 1-2 pages each). The high quality render limits the number of opened PDFs to six at the moment to stop the memory usage from getting too high (and it still can easily get over 300MB with a lot of PDFs with high DPI images), but this can cause some fighting over which songs get to have their PDF open for rendering purposes. There were some race conditions that could cause a song's PDF to be opened and closed in a fashion that messed up some of the code. I just put in some proper synchronization and everything is running smoothly now.

As a side note, I'm lowering the number of cached pages from 12 (current page + 7 forward and 4 back) to 9 (current page + 5 forward and 3 back) to lower the memory usage in the app. It can get dangerously high at the moment which is probably why I'm seeing a number of tablets with errors being thrown due to running out of memory.

Mike

[Steinway]

Thanks, hopefully this will have solved the problem!
Anyway, when I've seen the problem, my settings have been the following:

Portrait mode, single page. Render preference set to quality. All my songs are single file pdf's, and I almost never use setlists, so I've never had more than one file open when the black page has turned up. The three songs which have so far displayed the black page are all 20++ pages. Manually cropped within MSP, but some of the pages (usually every other page, when scanned from books) have been turned 180 degrees using Adobe 8. I have also used Adobe 8 to optimize the files.
As long as I wait a few seconds between each page turn (which, of course, I always do when performing) all page turns render instantaneously. Sometimes, when practicing, I may need to quickly turn several pages in a row, which may cause slightly longer rendering times (up to 1 or 2 seconds maybe). I have not done this, however, on the occasions when the black page has turned up.

[Steinway]

Quick update from nervous pianist: This just happened again, for the second time today, and even during an audition (not my own, but accompanying a trumpet player). And my assumption that the problem was only related to actually touching the screen proved wrong: this time I was turning with the pedals. Had to reload the song and start again, a bit embarrassing in front of a jury...
As a temporary solution, I will try changing the render preference for a while, and see if it helps.

[Zubersoft]

When you get a chance, can you try out the latest update to see if it makes any difference with the pages that don't render? Or did the problem happen even with version 1.3.9?

Thanks,
Mike

[Steinway]

I'm still using 1.3.8, so I will update today and see if it makes a difference. Thanks!

[Steinway]

I'm very sorry to bring back this thread, but sadly today the black page made its appearance again.. Now on 1.4.2..
Am I really the only one experiencing this? I really want to use the quality render mode, but I've started using only the speed rendering mode for performances, as I've yet to see the black page in this mode. I still use quality rendering when practicing however, ie when the black page appeared today. Any further information you could need in order to solve this? It's really giving me nightmares.. And it happens so rarely I still haven't found any single way to reproduce it..

[Zubersoft]

If you were just turning through pages at a normal rate and one didn't render, and it was an individual song, I have absolutely no idea why you would be seeing a page that never renders. I haven't had that happen on any of my tablets with individual songs, and I use the app every day on my HP Slate 21. Just to clarify - you didn't do anything like use the page slider, use a pedal, hit a corner with a tap action, pinch zoom or tap with two fingers, did you? I'm just trying to think of possible actions that would have caused the pages to re-render, and potentially create a scenario for a problem. Even if you did do any of those things, I'm still not sure how the page could be stuck like that, but at least I would have things I could look into.

[Steinway]

This time I didn't use a pedal (however, I have also seen the black page when using the pedals). No corner action is enabled. Turned using a single finger. Tried tapping the black page with two fingers, no effect. Tried entering annotation mode, wrote a few random lines on the still black page. Saved it, it now displayed as a black page with some lines on it. Tried pinch zooming, which forced the page to reload - displayed ok now. Turning the tablet to landscape mode also makes the page render correctly, i.e. anything which forces the page to reload solves the problem.

As far as I can recall, I believe I have always used the page slider when seeing this (though I'm not 100% sure of this).
One thing I noticed while trying to reproduce the problem today: If I select page 23 (for instance) on the page slider, page 23 starts loading for the fraction of a second, but before the page is displayed, the page slider jumps to page 24 or 25 by itself, and this page is loaded instead. This typically happens the first time I use the page slider after loading a song, subsequent page jumps seem to work as expected. May this somehow be connected to the problem?

[Zubersoft]

Are you tapping on the page slider, or pressing down, sliding it, and then releasing it?