Levak: strange. Are you testing on real HW or on nspire_emu?

HW :
TI-Nspire CAS ClickPad
OS 2.0.1.60
Boot2 : 1.4

Tested connected from computer, and disconnected from the computer.
I've tried at least my "workaround" with USB 3.0, it doesn't work better.

Here it is : an high framed shoot.

EDIT : OH MY GOD... stupid bug : The folder contains a dot. When I removed it, Ndless installs perfectly \o/

That's isalpha actually. TI's implementation of these functions is basically
int isalnum(int c) { return isdigit(c) || isalpha(c); }
int isalpha(int c) { return islower(c) || isupper(c); }
so it's very easy to confuse them if you're looking at a disassembly without symbols.

It's common practice for the standard C library to be implemented with one function per file, so the linker can omit any unused functions. That's probably what happened - whatever code used to use isalnum back in 1.7, got changed in 2.0.

Does anybody confirm the reboot Levak gets on real CAS hardware (i.e. it doesn't depend directly on the calculator state)?

Levak, according to your screenshot, the issue happens somewhere in stage1.c, and most probably in fopen since you don't have the third bar created by the fread. Either there is not enough memory to (f)open ndless_resources, or it simply cannot be found.

Could you please try the installation with much less files on the calculator, if it's not a problem for you to delete them?

I've said, by editing my post, that I managed to intall Ndless 2.0 on Hardware by removing the dot contained in the folder name.
=)

I get exactly the same screen on the emulator when I create a folder
named Ndless2.0 and put the Ndless files in there to run.

I tried the alpha version on my CAS Touchpad (OS 2.0.1, Boot2 1.4), and i got some issues :
  - when trying to install ndless, the installation often doesn't work : the calculator reboot most of the time.
  - All programs started, so no problem for that.
  - In all programs i tried, the touchpad  and a lot of keys didn't work at all.