I've been running BOINC (Milky Way and Einstein, for CPU and GPU respectively) for years (and distributed computing since SETI@Home was almost unique), a couple years without issues (I somehow got it to work after installing Kubuntu 22.04 a couple years ago) -- and we apparently still don't have a setup that will "just work" on Linux.

I had a notification today to download BOINC 8.0.2, and silly me, I grabbed it immediately and installed it. Now I somehow have Manager 7.22.1 (which might be correct for BOINC 8.0.2??), but when I launch it I get the dreaded "Invalid client RPC password. Try reinstalling BOINC" -- which experience says never works. There's a long thread https://boinc.berkeley.edu/forum_thread.php?id=14013 from 2020-2022 about this, with no clear conclusion as to how to fix it, but I'm certain my group membership and file configuration were okay half an hour ago, and now they're not.

I'm not a Linux guru, I just switched when WinXP was getting a little too vulnerable (thirteen years ago) and never had a good reason to put up with Microsoft since. This means I can paste (or type) a command sequence at the CLI, but I'm not really capable of researching for myself how to fix this -- I just like the idea of my computer contributing something useful to the world.

FWIW, as noted I'm running Kubuntu 22.04.4 on an AMD Fx8350, 32 GB DDR3 RAM, nVidia GTx2070, Milky Way and Einstein projects (once I can reconnect to them).

It occurs to me this may be a problem due to running the flatpak BOINC, and installing the .deb with "sudo apt install" as shown on the page linked from the notification.. Unfortunately, purging the apt-installed .deb (which was probably an older version from the repositories anyway) didn't help.

So, now that I'm back to (never left) the flatpak BOINC, how do I resolve the error above? Will waiting for the flatpak to update resolve the problem (I think installing the flatpak is what fixed this for me in 2022)?

Okay, good news and bad news: Apparently, purging the apt-installed version I was led to by the notification and then running "sudo flatpak repair .edu.berkeley.BOINC" (followed by a restart) has fixed my client -- but now I'm still getting a problem that popped up after a system update earlier this evening: "GPU Missing". I run flatpak nVidia drivers as well, and they're as up to date as they can be (no updates available). According to "sudo flatpak list" I have nVidia 535-171-04. The nVidia driver search says the current recommended version for my graphics card and OS is 550.90.07, though that was only released a couple weeks ago and likely hasn't made it into flatpak form yet...

Okay, following up, flatpak had an nVidia updated today, 535-183-01, and I'm now able to run GPU tasks again.

Still getting that message from flatpak that Gnome 44 (apparently used by flatpak BOINC) is EOL, though, and flatpak BOINC is still at manager version 7.22.1...

Using the instructions for Ubuntu here I have found they work straight out of the box for 8.0.2, 8.0.3 and the testing 8.1.0 (XUbuntu24.04)

I do get a message in the notices tab

Warning: GUI RPC password is empty. BOINC can be controlled by any user on this computer. See https://boinc.berkeley.edu/gui_rpc_passwd.php for more information.

Which is a non issue as I am the only user on the system.

Given BOINC is working under flatpak, I'm a little reluctant to uninstall it and try those instructions, as the last time I used apt to install BOINC I had the RPC password problem and couldn't get it resolved (hence why I switched to the flatpak).

Given BOINC is working under flatpak, I'm a little reluctant to uninstall it and try those instructions, as the last time I used apt to install BOINC I had the RPC password problem and couldn't get it resolved (hence why I switched to the flatpak).

can't say I blame you, knowing that under Windows files dictating how you use BOINC are left behind with a simple uninstall. I haven't used the flatpack to have tested that out.