Anki-android: V2.13: Answer buttons not appearing in Reviewer

[benjaminor]

Reproduction Steps

1. Select deck to review
2. Question page is nearly blank (only note and "show answer" button)
3. Right answer page is also blank

See pictures:

Expected Result

Question and answer page should be as usual, with the buttons there.

Debug info

AnkiDroid Version = 2.13.5

Android Version = 8.0.0

ACRA UUID = 80fce863-4876-45bc-9e26-1b657faa1f28

Scheduler = std

Research

Enter an [x] character to confirm the points below:

• [x] I have read the support page and am reporting a bug or enhancement request specific to AnkiDroid
• [x] I have checked the manual and the FAQ and could not find a solution to my issue
• [x] I have searched for similar existing issues here and on the user forum
• [ ] (Optional) I have confirmed the issue is not resolved in the latest alpha release (instructions)

[welcome[bot]]

Hello! 👋 Thanks for logging this issue. Please remember we are all volunteers here, so some patience may be required before we can get to the issue. Also remember that the fastest way to get resolution on an issue is to propose a change directly, https://github.com/ankidroid/Anki-Android/wiki/Contributing

[david-allison-1]

Hi @benjaminor, thanks for the report.

Could you confirm that this is an issue with 2.13.5:

Download https://github.com/ankidroid/Anki-Android/releases/download/v2.13.4/AnkiDroid-2.13.4.parallel.A.apk and see if this also has the same problem.

[david-allison-1]

I can't immediately see any reason why this should be happening: https://github.com/ankidroid/Anki-Android/compare/v2.13.4...v2.13.5

[david-allison-1]

@benjaminor,

Could you possibly export a deck which has this problem and upload it here, or to a file sharing site so we can ensure it's not a card template problem?

[benjaminor]

Hi @benjaminor, thanks for the report.

Could you confirm that this is an issue with 2.13.5:

Download https://github.com/ankidroid/Anki-Android/releases/download/v2.13.4/AnkiDroid-2.13.4.parallel.A.apk and see if this also has the same problem.

No, I can confirm this is also an issue with 2.13.4, should I also check out another version?

[david-allison-1]

Yes please, use Parallel.A when downloading. This will really help us track down the issue. Thank you!

https://github.com/ankidroid/Anki-Android/releases/tag/v2.12.1 - should be fine, you can download parallel.B and use this to review while we resolve the problem
https://github.com/ankidroid/Anki-Android/releases/tag/v2.13.0
https://github.com/ankidroid/Anki-Android/releases/tag/v2.13.1
https://github.com/ankidroid/Anki-Android/releases/tag/v2.13.2
https://github.com/ankidroid/Anki-Android/releases/tag/v2.13.3

[benjaminor]

As you said, v2.12.1 did not have the issue, but I could reproduce it with v2.13.0 and later.

Interestingly, the buttons still work, they are just not visible anymore. They disappear a short moment after I start the review.

[benjaminor]

@benjaminor,

Could you possibly export a deck which has this problem and upload it here, or to a file sharing site so we can ensure it's not a card template problem?

This one has the issue (all of my decks have), but I suspect the deck is probably not the cause, my decks are quite simple: https://nextcloud.orthen.net/index.php/s/8kLbZLwsTQEKgcj

[david-allison-1]

@benjaminor Could you try Settings - Advanced - Safe Display Mode on 2.13.5 and see if this fixes it?

Which phone are you using?

[benjaminor]

@benjaminor Could you try Settings - Advanced - Safe Display Mode on 2.13.5 and see if this fixes it?

Which phone are you using?

Unfortunately, this does not resolve the issue. (Neither does disabling the "Optimize battery usage" setting for the app.)

I can go on and test the v2.13.alphaX releases to do a bisect where the bug was introduced?

I'm using a Samsung Galaxy S7 (SM-G930U) which has Android 8.0.0, Samsung Experience Version 9.0 and a kernel 3.18.71-14970140 (if that helps you).

[hiacre]

I saw this exact same issue yesterday. It was working in the morning, and when I used AnkiDroid in the evening, found that the buttons (again/hard/good/easy) weren't appearing. I do not know if the Google Play Store automatically updated the app during the day or not. In addition, I could not see the OS UI when swiping up from the bottom of the phone (this has shortcuts for home, back, running tasks, etc). The OS UI was there (it reacted to presses), it just wasn't visible.

AnkiDroid version 2.13.5
Android version 8.0
Phone LG G5 (LG-H850)
Kernel 3.18.71-perf+
Settings > Advanced > Safe display mode set to "enabled" did not fix the problem.

I uninstalled the Google Store version of AnkiDroid, and began installing various tagged releases to find which versions worked and where the breakage appeared. I found that all versions I tried (2.12.1, 2.13alphaX, 2.13betaX, 2.13.X) worked.

When I reinstalled the Google Store version of AnkiDroid (v2.13.5), I found that I could no longer reproduce the issue.

[binarin]

I can see the same, but only on 1 of the 2 phones. Both have 2.13.5 installed. What's interesting is that all buttons (answer buttons at the bottom and menu bottom at the top) are just invisible, but they are clickable and do what they should. Reinstalling alone didn't help, but doing "Remove data" and "Clean cache" for that app solved the problem.

[ShrikeV]

I had same issue and confirm that "Remove data" and "Clean cache" solved the problem.

[terryneal2]

I also had the same issue and just 'Remove data' fixed it. Thanks everyone.

[mikehardy]

That is so bizarre - great work figuring out a workaround but I can't for the life of me figure out why that would fix it? :thinking:

[hiacre]

Just to update on my experience - I didn't use the "remove data" option. Instead I reinstalled v2.13.5 which helped (not sure if that's equivalent to "remove data" or not). About 11 hours later, the problem returned. I've now downgraded to v2.13.0, and will do a minor version upgrade every couple of days to find out if there's a particular version where the problem cuts in.

One thing I noticed that might be helpful: when the problem returned, it exhibited itself slightly differently. I started a review, and the question appeared with no top menu bar at all. Then, within about a second, it flickered into visibility. That is, it seemed to rapidly disappear then reappear until it settled on being visible. After a few rounds of seeing this behaviour, it decided to stop showing itself altogether.

[hiacre]

New observation: after downgrading to v2.13.0, everything seemed fine for about 36 hours. When I started up AnkiDroid today, I was presented with the AnkiDroid Changelog screen which has a bar at the top (showing back button, and "AnkiDroid v2.13.5") and a bar at the bottom (showing the buttons "Rate AnkiDroid" and "Continue"). As I scroll up and down the changelog, the top and bottom bars flicker like crazy (the buttons in the bar at the bottom do NOT flicker). When I stop scrolling, there is about a 1 in 3 chance that both bars disappear (but the buttons at the bottom are still visible). I thought this was so similar to the reported problem that it was worth mentioning.

It appears I have been auto-upgraded to v2.13.5, I'm not sure if AnkiDroid did this itself or if the Google Play store did this. I'm positive I installed from the v2.13.0 APK... perhaps I was mistaken. EDIT: I was on v2.13.0 and was auto-upgraded by Google Play Store, have now turned off auto-updates.

[mikehardy]

Yeah, play store will auto-update you, which is normally exactly what you want. But not if attempting to isolate one version where things break of course :-)

[david-allison-1]

New observation: after downgrading to v2.13.0, everything seemed fine for about 36 hours. When I started up AnkiDroid today, I was presented with the AnkiDroid Changelog screen which has a bar at the top (showing back button, and "AnkiDroid v2.13.5") and a bar at the bottom (showing the buttons "Rate AnkiDroid" and "Continue"). As I scroll up and down the changelog, the top and bottom bars flicker like crazy (the buttons in the bar at the bottom do NOT flicker). When I stop scrolling, there is about a 1 in 3 chance that both bars disappear (but the buttons at the bottom are still visible). I thought this was so similar to the reported problem that it was worth mentioning.

Is there any possibility that you (or anyone) could send a video of this? Especially on the changelog/ Settings- Advanced - About AnkiDroid screen.

Are there any settings that you're changing before this appears (full screen for example), or does this appear seemingly at random?

[hiacre]

I've only ever seen the Changelog screen after launching the app after an update. Is there another way to view it? I'm not sure how useful the Settings->Advanced->About AnkiDroid screen will be, because all the text fits on the screen, so it's not possible to scroll up and down.

I didn't change any settings, as I'm happy with the defaults (I had no idea there was a fullscreen mode!) The weird behaviour starts up seemingly at random.

I attempted to reproduce just now by upgrading from v2.13.0 to v2.13.5. I saw flickering on the changelog screen as I scrolled up and down. The flickering was on the top bar, but no flickering on the bottom (possibly because it's a white bar on a white background - when I spotted this before, I was using Night Mode). I started up AZ Screen Recorder to take a video, but the act of doing this fixed the flickering problem. I'll have to find a second phone next time it happens.

It made me wonder whether it's related to overlay apps. I have a blue light filter installed, but it has worked fine with all other apps (and all other versions of AnkiDroid).

[hiacre]

I managed to grab a video of the flicker, after updating from v2.13.0 to v2.13.5.

https://www.dropbox.com/s/abznbno1bizgajf/AnkiDroid%20Issue%207369%20changelog%20flicker.mp4?dl=0

I turned on "Night mode", so that the bottom bar flickering could be seen as well. After I took this video, I attempted to use the AZ Screen Recorder again, but (again) doing that resolved the issue.

[david-allison-1]

Thanks for the video!

Could you download the 2.12 parallel release and confirm that the issue doesn't occur (especially if reports say it comes and goes after ~48 hours): https://github.com/ankidroid/Anki-Android/releases/download/v2.12.1/AnkiDroid-2.12.1.parallel.A.apk

The video implies to me that this is a hardware rendering issue, but, the fact that this occurred on a version upgrade implies that there may be something more to it.

I'll guess that it could potentially be one of the following updates:

    implementation 'com.google.android.material:material:1.2.0'
    implementation 'androidx.appcompat:appcompat:1.2.0'

---

Could you also test the Parallel.B of:

2.13alpha 9: https://github.com/ankidroid/Anki-Android/releases/tag/v2.13alpha9
2.13alpha 11: https://github.com/ankidroid/Anki-Android/releases/tag/v2.13alpha11
2.13alpha 13: https://github.com/ankidroid/Anki-Android/releases/tag/v2.13alpha13

and see if these do or don't exhibit this problem?

[mikehardy]

...been watching this (thanks for the video and reproduction efforts, sincerely!) and was thinking the same on those two dependency updates as "maybe"s

[hiacre]

I've been using the v2.12.1 parallel A release for 48 hours now, no sign of any problems. I'll move on to the v2.13 alphas next.

[hiacre]

I've been using parallel B of v2.13alpha9 for about 48 hours now, with no problems.

[hiacre]

I've been using parallel B of v2.13alpha11 for about 3 days now, with no problems. I'll move on to v2.13alpha13 next.

[moksamedia]

I've got the same problem here. LG G6, Android version 8.0.0. Had been working great for many months. Just broke recently.

[david-allison-1]

Hi @moksamedia

For now, could you download and use a parallel release of 2.12.1 to work around the problem: https://github.com/ankidroid/Anki-Android/releases/v2.12.1

It'd be useful if you could take some time to isolate the alpha release which introduced this bug. It's between 2.13.0 and 2.13alpha11: https://github.com/ankidroid/Anki-Android/releases?after=v2.13.0

We haven't been able to replicate this on our emulators, it seems to be physical-device only, so any help is appreciated.

[hiacre]

I've been using parallel B of v2.13alpha13 for 3 days now, and I haven't seen any sign of the problems. I'm going to start doing a binary split search across all the releases between v2.13alpha13 and v2.13.5.

[david-allison-1]

Can't reproduce this with the Samsung Galaxy Test Lab Samsung Galaxy S7

[hiacre]

I've been using v2.13.4 (parallel B) for 15 days now, and haven't seen any problems. From my perspective, it appears the problem was introduced in v2.13.5. However, the original reporter stated that they were able to reproduce in v2.13.0 and later. I suppose I could upgrade to v2.13.5, to find out whether:

1. if the problem appears relatively soon (within a few days) - in this case I think that shows there's something between 2.13.4 and 2.13.5 that triggers the problem. The 2.13.4 -> 2.13.5 change could be the entire problem, or it could be exacerbating an existing problem introduced in an earlier version that does not exhibit itself on my phone.

   1. if the problem does not appear, then perhaps it was just a transient problem introduced in some unknown version, and fixed by reinstalling or wiping caches and app data.