I can´t update sources in LIVE USB MX Linux

I am trying to update sources to update my LIVE USB MX Linux 23.1 system but when I launch the MX Package Installer I find this error:

 1 error updating sources.jpg   76.78KB   0 downloads

Then I select a kernel to update and I click "Install":

 2 kernel instalation screen.jpg   86.02KB   0 downloads

The result is an error refreshing sources:

 3 refresing sources error.jpg   137.76KB   0 downloads

It returns a message error log like this:

 4 mxpi.log.jpg   159.89KB   0 downloads

And the complete log here (is small):   mxpi.log   6.3KB   0 downloads

I have tried to do a remaster but the result is the same.

And when I execute the LIVE USB Kernel Updater only detects "Memory Test" like new kernels installed... I have not executed this update because first the kernel must be installed with the MX Package Installer and then well detected by the LIVE USB Kernel Updater.

Please help me!. I cannot update anything like kernel or applications. I hope that some messages in spanish language doesn´t be a problem, If so, please translate it with an online service or ask me.

Thank you very much!

Edited by digitoforo, 15 December 2023 - 03:24 PM.

If I recall, a LIVE USB key sets the running OS in Read Only mode.  You can fix your other Read/Write partitions with it, but can't touch the running OS.

I am using the Persistence mode. This means that I can made changes in the system between reboots.In fact the MX LIVE USB systems have a specific tool for update the kernel. This obviously means that changes like that can be made. I have updated the kernelI in the past in this type of system, but now I have an issue with the sources. Please someone with experience in MX LIVE USB systems can help. 

Edited by digitoforo, 16 December 2023 - 04:18 AM.

My Spanish is a bit rusty, but it looks like there's an issue with the GPG key for one of the repos. Seems the public key is missing, based on the error.

Hello again.
I have executed MX Fix GPG Keys but it doesn´t make changes, it doesn´t find errors...
I think the issue can be with protonvpn. Maybe because of try to install something or update protonvpn with the MX Package Manager with the Proton APP working at the same time.
I solved this by following this and only this steps:

1-Setup the Kill Switch from "Permanent" to "On", if it was not.
2-Exit from the Proton APP.
3-Execute the MX Package Manager and install the new kernel.
4-Execute the LIVE USB kernel updater and follow the instructions...

The issue now comes when I try to make a snapshot of all the LIVE system to an iso, the MX Snapshot application outputs it detects a change in the size of the overall system and cannot continue. Then I tried to reboot and the kernel outputs a similar message and cannot boot.

I decide to dump a previous snapshot to the pendrive with Rufus and begin again...

The kernel that I have installed before this mess is the 6.6, someone that knows this issue or if comes by this kernel in LIVE systems or something?

Edited by digitoforo, 16 December 2023 - 04:17 PM.