It started happening after today's update:
https://imgur.com/a/Kcyx0NI
New Editor Extensions or Freeplay maps also crash instead of loading.

Same.
Is there anything I can do?
My game is stopped and I'm afraid of losing my save 😅

Same issue here after update 1.1.107.

Hello everyone, I also encountered this issue preventing me from entering the game. Since I don't know when the author will update, I've temporarily fixed the code using an AI. Currently, I'm able to play the game normally. If you can't wait, you can download the file for temporary use.
https://drive.google.com/file/d/1KuaeBq_YwnMMAZs4C5mER50ddM4zDttg
Instructions: Download "profiler.lua" and open (but do not extract) the "ammo-loader_1.1.38.zip" file using an unzip tool. Navigate to "src\lib" and replace the existing "profiler.lua" with the downloaded one. Now you should be able to enter the game. Lastly, I hope the author will update soon.

Same here

453.195 Error AppManagerStates.cpp:1659: ammo-loader/lib/profiler.lua:22: table index is nil
stack traceback:
ammo-loader/lib/profiler.lua:22: in main chunk
[C]: in function 'require'
ammo-loader/control.lua:9: in main chunk

The devs removed a Debug library, and ironically, the mod has a line to IGNORE this library, but now this library doenst exist and the mod is trying to ignore something that doesnt exist...
The fix from Yavis1231 works and i dont think it will inpact the mod in any way.

The devs removed a Debug library, and ironically, the mod has a line to IGNORE this library, but now this library doenst exist and the mod is trying to ignore something that doesnt exist...
The fix from Yavis1231 works and i dont think it will inpact the mod in any way.

Its not that simple, the boolean key is used throughout the code in a lot of other places. I have no idea why but its there, the fix wouldn't be as simple as asking some dumb AI to fix it.

"the fix wouldn't be as simple as asking some dumb AI to fix it."
Well, this is LITERALLY a situation that a "dumb AI" fixed.... so..... what was your point again?

The point is: if the dumb AI fixed the issue, new issues wouldn't be created on the same matter. Which isn't the case.
But you're free to do whatever you please. If you think that a dumb AI can fix any mod, send PR with the fixes so everyone would benefit from it.

I deleted ammo-loader_1.1.38\lib\profiler.lua and then removed the call for the file and profiler code block from the start of control.lua. This allowed my saved game to load without the aforementioned errors.

I deleted ammo-loader_1.1.38\lib\profiler.lua and then removed the call for the file and profiler code block from the start of control.lua. This allowed my saved game to load without the aforementioned errors.

This worked for me, too. Thought I lost a 2k hour save.

Yep, worked for me too. Maybe the AI isn't so "dumb" ;-)

Anyway, this is appears to be a possible work-around to keep your save going until silent gets a chance to have a look.

I deleted ammo-loader_1.1.38\lib\profiler.lua and then removed the call for the file and profiler code block from the start of control.lua. This allowed my saved game to load without the aforementioned errors.

Why delete profiler.lua if you removed the call from control.lua. Is it being used anywhere else that made it necessary to delete the file itself? 🤔

Sorry guys for the long delay! I just uploaded 1.1.39 with a fix.

Thank you to yavis1231 for picking up my slack and providing a temporary fix! I owe you one!

TexugoMaldito correctly surmised the issue:

The devs removed a Debug library, and ironically, the mod has a line to IGNORE this library, but now this library doenst exist and the mod is trying to ignore something that doesnt exist...

The library file in question (profiler.lua) is a third party library I used in previous versions when testing performance. The wonderful devs at Wube have since provided much more refined profiling tools of their own, and as such I have not used the library in some time. In the newest version, I have deleted the library and all references to it from the mod.

Regarding the AI discussion...
The AI's fix does work and is harmless as TexugoMaldito said. However, Mobius1 also had a very good point about the AI's lack of context. The fix only worked because I no longer used the library in question in any part of the code except to import it during the mod's initialization. With the changes the AI made, the Profiler class would be completely broken and would crash the game if called to do anything. Glendening's alternative fix is much safer and is essentially what I ended up doing.

Lastly, thanks for using my mod and being part of the Factorio modding community! I know you could have easily just wrote my mod off (as I'm sure many did), but I'm thankful that you all were willing to put in the effort to troubleshoot it instead despite my irresponsible lack of response to this major issue. I hope I'm able to continue being a part of this wonderful community!

Hi silentcrim. Tx for the update and for the answer about the differents tactics use to resolve the issue while you make the fix.
I was waiting in patience with my not so old 1.11.106 version but i check the differents solutions and the ia one, even valid, don't seduce me.
For sure factorio has a great community.