I have lost hours of work twice now in less than 24 hours. I don’t understand why, but Thunkable is either not saving what I’m doing or it’s resetting my work back. I just rebuilt like 3-4 hours of work (both design and blocks). I’d seen someone recommend creating a duplicate of their project as a safeguard against this, so I did that. I come back to start again after taking a 2 hour break and almost everything I rebuilt is gone. AGAIN. Additionally, my duplicate project that I created after I rebuilt has also been set backwards to the same place. I am so upset. This is my first Thunkable experience and I’ve devoted so much time to learning and troubleshooting. Retracing my steps is super difficult because everything I do I have to look up documentation, watch tutorials, try and fail a few times, etc. What is going on??
I’ve experienced this as well, but not to the degree you’re dealing with missing hours of work.
When this has happened to me, I closed all open instances of the browser, reopened the browser and made a few small changes to my app, closed the browser again, reopened the app and if they stuck I kept working. If they were gone, I repeated those steps until things were working again… I can’t tell you why. 
Hello @keenspace @marion.dorsett
Our engineering team was able to identify the root cause and is working on a fix.
We’re committed to finding a resolution quickly, and we will keep you updated as soon as there is any progress.
Thank you again for alerting us to this issue and for your time and patience while we work to resolve it.
Same experience, but with “Tons” replaced by “Kilos” 
!
But still quite annoying…
Hope a fix will be soon found!
I hope there is a solution to my problem, this morning while I was arranging some little things in the blocks of a screen I found myself without any blocks, the drawing part of the screen remained but its blocks did not!
Is there a way to take a step back and recover the lost blocks?
thank you very much.
Hello @vico3341rys8kx
I moved your post here so we can easily track similar issues
@motzet @marion.dorsett @keenspace
Is your Thunkable account logged in anywhere else? Even on a mobile browser or any place like that?
Do you have the same project open on another device or browser?
Being logged in on multiple devices can cause this behavior.
Not in my case. I use Firefox as my primary browser, and I use Chrome for Thunkable and a few other visual builder apps that I use.
I use my email to log in and have to click the link when it expires, and I will either copy the link from Firefox, or log in to my email on Chrome and click the link directly in Chrome.
I would say that when I lost progress, it was more likely that i was switching back and forth between projects. I would help someone on the forum, find a solution in a testing app, and then use what I needed from that solution and put it back into my app.
It sounds like the issue is that more than one session could be editing the same app and overwriting the app instance. If that’s the case, please make sure that he app isn’t “locked” indefinitely. For example, if you edit a post in WordPress and don’t exit out of the page and then try to edit that same post in a different session (even in the same browser) WordPress will let you take over the editor. This prevents the user (me) from having to drive back to the office to shut down the other browser session before I can resume working on the project from a different location.
Thank you.
Hi,
Sorry, but my Thinkable account is only logged on one computer (Apple MacBook Air) !
Waiting for another suggestion…
Hope you will soon find a solution.
Hi,
Maybe I’ve noticed something which could help:
When working on a new version of a project I just labelled it “Project-1”, “Project-2”, etc. and then I’m experiencing problems : i.e it doesn’t save the project like it did several days before!
But if I rename the different versions, for exemple “Ex-Project-1”, “Ex-Project-2”,… then the saving seems to be quite correct!
Could be that if several project names begin with the same string makes trouble ???
Hope this remark could help.
@vico3341rys8kx @vico3341rys8kx @marion.dorsett @keenspace Please accept our sincerest apologies for this issue. The root cause is still being investigated. We’ll be sure to let you know as soon as we’re able to identify the cause and get a timeline for any fixes.
I would like to propose if possible to implement something that saves the work done so that it can be recovered if what happened happens.
Yes, even I lost around 500 blocks of a screen + lots of design work
Sorry to hear about this @longcodes22kpn5, rest assured that we have flagged this issue with the utmost urgency and will be in touch as soon as we can find a fix.
I’m not sure if Thunkable has an auto-save feature. I created a screen, closed the tab, and when I reopened it, the screen wasn’t there. Is there an option to save screens immediately to ensure they’re saved?
@vico3341rys8kx @longcodes22kpn5 @motzet @keenspace we were able to deploy a fix that should help remedy the issue, if not resolve it completely. Let us know when you have a chance if you’re seeing an improvement in the work saving. Thank you!
Welcome to Thunkable! 
Be sure to check out How to ask Great Questions v2.0, the Community Guidelines, and our Getting Started Guide to make the best of your Thunkable Community experience!
I’ve merged your topic here as we are aware of a current known issue involving project progress not always saving. We have deployed a fix that should help remedy the issue, if not resolve it completely. Are you still having this issue?
Thank you!
Tks a lot! Problem “Not saving” seems to be solved. 
One more question: would’nt be possible to add some feature like “Undoing last action” ?
Because it happens sometimes that I delete blocs unintentionally…
Glad to hear this!
We are developing some functionality toward an undo feature currently. That is undergoing some testing internally and we hope to have the beginnings of this feature released to the public soon. We’ll be sure to make an announcement here in the Community when that happens!
Although there seems to be a “we’ve fixed it” post a few days ago I seem to still be having this issue … I’ve had a “crash” (screen just froze, so killed the page) which lost work (somewhat understandable) … BUT I’ve also just had work “vanish” just now … I stopped for a coffee having closed the browser and both the work I just did AND it’s mirror in the “duplicated” copy I made before I stopped were gone.
Is it actually fixed, can we not just “save” locally & manually or soemthing!?
Hi @adrianbgardnerphe4dl, everything we’ve seen in other scenarios previously reported so far has been positive for the fix having worked.
Could you share the link for the project(s) where you are seeing this issue? I can have someone look into it.