The issue is present in older Apple devices that are still using the 32bit processor. We’ve submitted a fix and it will be available as soon as it passes Apple review.
A masive thank you to all that reported this issue and keep an eye out for the next update.
Thanks for getting back to us so quickly!
In the meantime, until the fix for this is available, is there any way to revert back to the working pre-updated version?
Can I delete the current, non-working version and download the older version somehow?
I don’t want to let my language-learning suffer by missing daily practice 
It isn’t easy. One of the several links I found after a quick Google for “ios revert app update”:
https://www.cultofmac.com/403848/how-to-restore-older-versions-of-ios-apps/
The fix is now out. A simple update should get everything back in working order.
Happy learning
Beatrisy
I downloaded version v2.3.28.6785, deleted and reinstalled, logged in again and I still have this bug using, for example, American Sign Language 2. Spanish (Mexico) 1 appears to work though.
@BeaTrisy, this error still happens. I’m on the latest Memrise verison (have deleted and reinstalled app), iOS 11.4 with iPhone 7s.
I notice this is with courses/levels that use images as the Question / Answer.
On new level, i.e. Learning New Words lesson, I get an error “There is nothing to learn in this game mode”
On levels I’ve started, i.e. Review lessons, I get the error LearnableSourceError
Example A course, Aleinu Demo - Memrise
Example B course, Rashi Script - Memrise
Example C course level 2, https://www.memrise.com/course/1333985/biblical-hebrew-aleinu-prayer-siddur-w-audio/
I’m seeing this with some courses, as well – long-standing issue.
The same problem.
@BeaTrisy issue still persists with latest Memrise update – 2.3.30.6943. Also, I deleted and reinstalled app.
Any update? This is a blocker error for any course dependent on images as content.
Oh reinstallation of app neither helps, was going to do this. Sounds like something they really need to fix now as there’s no workaround.
@MemriseSupport hi there, just checking if the iOS team is aware that this issue still persists. Thx!
Many Thanks - I have asked the iOS and QA teams to re-open this case to investigate. Hope to have some answers shortly.
You the man. Thx!
Is there any progress on this? I have not been able to use my iphone Memrise app for weeks now!
Any update here? I’ve downloaded the latest app version (2.3.31.7018), deleted and reinstalled app and problem still persists. @MemriseSupport @MemriseMatty @BeaTrisy
Hi - Our team is working on it, but we’re still investigating these errors. It looks like the error is intermittent on our end, although it appears for certain users consistently. Thanks for all the details so far. Hope to have some answers and fixes shortly.
The latest version (2.3.32.7080) seems to have fixed the problem, for me at least. Thanks.
I’m getting this error on iOS in the Japanese 3 course: https://www.memrise.com/course/1389173/japanese-3/
I’m seeing a different “words learned” count on iOS (641 / 641 words learned) vs the desktop web (639 / 639 words learned).
So on iOS I’m stuck on 2 words left to review. When I try to review, I get the error.
