Lesson session sometimes gets stuck

I’ve had this problem several times now, but it’s only today that I’ve decided to report it. Basically, when I do my lesson session and sort of wander away to do some other stuff for some time (because I can’t concentrate much), when I return, the session kinda gets “stuck”, so I can’t advance to the next item or return to the previous one, the arrow buttons on the sides and the item buttons below do nothing (the arrow buttons actually only work on the current item, but do nothing when it’s supposed to go to the next tiem), or rather they give an error in JavaScript console.


It may be the userscript that causes it, but I’m not sure.

Errors as a text:

userscript.html?id=9e767782-210e-459f-904b-fa83978e98bc:424 Uncaught TypeError: Cannot read property ‘concat’ of null
at Array.toggler (userscript.html?id=9e767782-210e-459f-904b-fa83978e98bc:424)
at r (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:58)
at c (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:58)
2application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96 Uncaught TypeError: Cannot read property ‘2’ of null
at HTMLLIElement. (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96)
at HTMLLIElement.dispatch (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at HTMLLIElement.m.handle (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:25)
2application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96 Uncaught TypeError: Cannot read property ‘0’ of null
at HTMLLIElement. (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96)
at HTMLLIElement.dispatch (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at HTMLLIElement.m.handle (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:25)
application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96 Uncaught TypeError: Cannot read property ‘1’ of null
at HTMLLIElement. (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96)
at HTMLLIElement.dispatch (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at HTMLLIElement.m.handle (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:25)
at Object.trigger (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at HTMLLIElement. (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at Function.each (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:14)
at pe.fn.init.each (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:14)
at pe.fn.init.trigger (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at Object.prevItem (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96)
at n (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96)
application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96 Uncaught TypeError: Cannot read property ‘0’ of null
at HTMLLIElement. (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96)
at HTMLLIElement.dispatch (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at HTMLLIElement.m.handle (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:25)
at Object.trigger (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at HTMLLIElement. (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at Function.each (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:14)
at pe.fn.init.each (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:14)
at pe.fn.init.trigger (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at Object.prevItem (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96)
at n (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96)
application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96 Uncaught TypeError: Cannot read property ‘4’ of null
at HTMLLIElement. (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96)
at HTMLLIElement.dispatch (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at HTMLLIElement.m.handle (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:25)
at Object.trigger (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at HTMLLIElement. (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at Function.each (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:14)
at pe.fn.init.each (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:14)
at pe.fn.init.trigger (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at Object.prevItem (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96)
at n (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96)
3application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96 Uncaught TypeError: Cannot read property ‘2’ of null
at HTMLLIElement. (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96)
at HTMLLIElement.dispatch (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at HTMLLIElement.m.handle (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:25)
(anonymous) @ application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96
dispatch @ application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26
m.handle @ application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:25
application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96 Uncaught TypeError: Cannot read property ‘1’ of null
at HTMLLIElement. (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96)
at HTMLLIElement.dispatch (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at HTMLLIElement.m.handle (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:25)

Seems like it’s the userscript…

I mean, I can’t really reproduce the problem, but I’ll turn the script off and see if that helps, although judging from the errors I think that the userscript errors on something being wrong in the app, but I’m by no means an expert at JS, so I’ll leave it to others.

How long are you letting the lesson stay idle? It will time out after a certain period of time. You can set the lesson batch down to 3 if 5 items at a time is too much for you.

You could also just refresh and speed through the items you’ve already looked over.

1 Like

The problem is that when I refresh the page the items get mixed up again so the ones that I looked through get moved later in queue.

Huh, that seems quite strange. Do you have the same experience when closing the browser and opening a fresh tab?

Didn’t check it, probably would be the same.

I think that’s a side effect of using the Reorder script. If you don’t use a lesson order script at all, or use Lesson Filter you wouldn’t have that problem.

1 Like

Lesson Filter seems ok, I’ll try it, thanks!

1 Like

It’s more likely that the userscript doesn’t gracefully handle the idle timeout and just errors out.

Update: It happened again, without Reorder Ultimate. And although I had Lesson Filter, I wasn’t using it.

Errors

application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96 Uncaught TypeError: Cannot read property ‘length’ of null
at Array. (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96)
at r (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:58)
at c (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:58)
application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96 Uncaught TypeError: Cannot read property ‘3’ of null
at HTMLLIElement. (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96)
at HTMLLIElement.dispatch (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at HTMLLIElement.m.handle (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:25)
application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96 Uncaught TypeError: Cannot read property ‘4’ of null
at HTMLLIElement. (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96)
at HTMLLIElement.dispatch (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at HTMLLIElement.m.handle (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:25)
application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96 Uncaught TypeError: Cannot read property ‘3’ of null
at HTMLLIElement. (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96)
at HTMLLIElement.dispatch (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at HTMLLIElement.m.handle (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:25)
application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96 Uncaught TypeError: Cannot read property ‘2’ of null
at HTMLLIElement. (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96)
at HTMLLIElement.dispatch (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at HTMLLIElement.m.handle (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:25)
application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96 Uncaught TypeError: Cannot read property ‘3’ of null
at HTMLLIElement. (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:96)
at HTMLLIElement.dispatch (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:26)
at HTMLLIElement.m.handle (application-d3336a7fbfc736af2217ee5088f57ea0f9ce69e0764063606df527b3c61e9305.js:25)

Afraid I don’t have any other ideas then. Good luck.

What other scripts do you have?

WaniKani Override, but it’s probably okay.

Scrap that and get Double-Check instead. Override has not been maintained for years.

Ok, I’ll use double check instead, although I doubt that it will solve the problem because override script is not even active in lessons, so… Could be a bug in WK itself.

OP, I was having the same problem with lesson sessions sometimes getting stuck. Since I’m not using any userscripts, I contacted WK and Rachel got back to me and suggested I try a different browser. When I switched from using Safari to using Google Chrome the problem completely went away. Just my personal experience which may or may not be useful to you.

It still happens to me sometimes, so idk, probably a Chrome only issue. Not that it bothers me too much now, but it’s probably something that needs either a fix, or a “Your lesson session has timed out” message, which sometimes appears, sometimes doesn’t.

1 Like

Hey I was looking for someone having the same issue and saw your post.

So the idea is your reviews / lessons are not stuck it’s just the memory of your navigator being really heavy… You may also have had a popup from time to time saying your cache for chrome / safari / firefox is up to 3/4/5 gigas.

Next time it’s “stuck” just wait like 20 seconds or so you will see everything comes back to normal afterward.

I was looking for a way to improve that ^^"

If you free your cache you won’t have this issue anymore but you will have to setup everything again (from reorders to your daily review’s done colors…) :slight_smile: