uname -r
apt policy linux-image-amd64

And look in /lib/modules to see if that directory exists.

Wild guess: you upgraded to daedalus but didn't upgrade the kernel because the kernel metapackage is not installed. (linux-image-amd64)  That package pulls in the latest kernel for the release you're running.

Or you booted into an older kernel by mistake.

Yes, I would say so.

I'm afraid that you are not giving us enough information.

That said, something does seem to be amiss.

To wit:
My latest (recently updated) Devuan Daedalus system has a /lib/modules/6.1.0-45 directory.

$ uname -a
Linux devuan 6.1.0-45-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.170-1 (2026-04-30) x86_64 GNU/Linux
$ 
$ ls /lib/modules
6.1.0-45-amd64
$ 

A VM I run on an updated Devuan Chimaera system has a /lib/modules/5.10.0-9 directory

$ uname -a
Linux chimaera 5.10.0-9-amd64 #1 SMP Debian 5.10.70-1 (2021-09-30) x86_64 GNU/Linux
$ 
$ ls /lib/modules
5.10.0-9-amd64
$

See the inconsistency?
ie:
Daedalus -> 6.1.0-45-amd64
Chimaera -> 5.10.0-9-amd64

What package are you attempting to install in your Devuan Daedalus system?
Is it from the Devuan repositories and installed through synaptic, apt or apt-get?

Best,

A.

I updated some packages (daedalus) which were classified (in terminal) as kept back and got this message

depmod: WARNING: could not open modules.builtin.modinfo at /var/tmp/mkinitramfs_l7Dri7/lib/modules/5.10.0-9-amd64: No such file or directory

Is this a problem? If so, how to fix it?