Hi there.
This forum is run by the community, so it's not like it's a 24/7 manned support ticket system like there is on https://support.openvpn.net/ - for anyone reading this in the future, if you need assistance with OpenVPN Access Server, that's where you should go, and we guarantee a very fast return time there. I am confident if you had submitted your question there you would have had an answer within a few hours at the most.
Regarding posts on the forums needing approval - yeah, that's unfortunately needed or else we would be flooded with spam. There is no easy way to protect against that these days thanks to AI. Typical things like captcha and email verification, while still a good idea, don't fully work anymore, as AI can solve that too these days. So regrettably we have to have someone come in and manually approve posts. And that takes time. It can't be helped.
Regarding the official changelog, it mentions this:
The new OpenVPN core also switches to the new DCO kernel module code, based on the upstreamed Linux kernel 6.16+ DCO code. This means it can use DCO if your Linux kernel is version 6.16 or newer and includes the DCO code. It is also offered as an installable module to support DCO on older Linux kernels and to access the latest features and updates. If you rely on DCO, verify after upgrading your Access Server that DCO support is working correctly.
On Access Server versions older than 3.2.0, OpenVPN core 2.6.x or older was used. Those still used the old DCO kernel code module. By old I mean that it was the iteration of the DCO kernel code before it was upstreamed to the Linux kernel (since version 6.16). During the process of upstreaming the DCO code to the Linux kernel, so it is part of the Linux mainline kernel without requiring to install a separate DKMS managed kernel module, the code was significantly altered and improved. So the old module is not going to be updated with the new code. The new version of DCO that was upstreamed is being offered for older Linux kernels as a completely separate module and is designed to work with OpenVPN 2.7 and newer only. So the old code for old OpenVPN, new code for new OpenVPN.
Access Server 3.2.0 and newer use the newer OpenVPN 2.7 and thus must also use the new DCO code.
If your Linux kernel is 6.16 or newer, the DCO code is actually built into the Linux kernel. You don't even need to install a module if you have a reasonably modern Linux kernel. Over time this means noone will need to install a separate module to get DCO support. In your case though it seems you have an older Linux kernel or perhaps a custom compiled one without the DCO code in there. For those cases we still offer the new DCO module as a separately installable module and you can install it using the commands you posted. That's why we encourage people to check after upgrading if they need this or not. Some won't and some will.
I understand that it is annoying to have to deal with fixing the situation after an upgrade, but at the same time I do want to highlight that nothing will break. Without DCO, the Access Server will function completely, and there will be no interruptions to your connections. It just means the performance will be less than it can be with DCO.
Some people will upgrade and have a modern Linux kernel that contains DCO and they won't even need to install the new DCO module. But for those with older Linux kernels, yeah, they can install the new optional DCO kernel module, and restore the performance benefit of DCO.
