slackpkg GPG problem (key not found)

I use slackpkg+ and have multilib enabled.

After an upgrade of slackware current, slackpkg update gpg gives me the following error:

Code:# slackpkg update gpg

http://ftp.nluug.nl/os/Linux/distr/slackware/slackware64-15.0/GPG-KEY:
2021-07-17 22:02:05 ERROR 404: Not Found.
gpg: processing message failed: eof
gpg: processing message failed: eof

!!! F A T A L !!!
Slackware repository does NOT contain the Official GPG-KEY
You SHOULD disable GPG Strict check 'STRICTGPG=off'
in /etc/slackpkg/slackpkgplus.conf

failed: Connection refused.

!!! W A R N I N G !!!
Repository 'slackpkgplus' does NOT contain the GPG-KEY
You SHOULD disable GPG check by setting 'CHECKGPG=off'
in /etc/slackpkg/slackpkg.conf or use slackpkg with
'-checkgpg=off' : 'slackpkg -checkgpg=off install packge'

2021-07-17 22:02:14 URL:https://slackware.nl/people/alien/multilib/current/GPG-KEY [11137/11137] -> "/tmp/slackpkg.zjsYkQ/gpgkey-tmp-multilib" [1]
pub 1024D/A75CBDA0 2003-01-17 Eric Hameleers (IBM Linux) <alien@linux.vnet.ibm.com>
uid Eric Hameleers (Thuis) <e.hameleers@chello.nl>
uid Eric Hameleers (IBM Linux) <alien@nl.ibm.com>
uid Eric Hameleers <eric.hameleers@int.greenpeace.org>
uid Eric Hameleers <alien@sox.homeip.net>
uid Eric Hameleers <alien@slackware.com>
uid [jpeg image of size 3054]
uid Eric Hameleers (SBo) <alien@slackbuilds.org>
sub 1792g/7CBDC819 2003-01-17
gpg: key A75CBDA0: "Eric Hameleers <alien@slackware.com>" not changed
gpg: Total number processed: 1
gpg: unchanged: 1

==============================================================================
WARNING! One or more errors occurred while slackpkg was running
------------------------------------------------------------------------------
Fatal: Slackware repository does not contains the official gpg-key!!
gpg: processing message failed: eofCould someone shed some light on this? It never made this complain before ...