After successfully installing "apt4suse" I attempted to install synaptic and got this error: # apt-get install synaptic
Reading Package Lists... Done
Building Dependency Tree... Done
The following extra packages will be installed:
docbook_4 iso_ent libzvt scrollkeeper sgml-skel xmlcharent xsu
The following NEW packages will be installed:
docbook_4 iso_ent libzvt scrollkeeper sgml-skel synaptic xmlcharent xsu
0 upgraded, 8 newly installed, 0 removed and 116 not upgraded.
Need to get 0B/3574kB of archives.
After unpacking 13.7MB of additional disk space will be used.
Do you want to continue? [Y/n] Y
Checking GPG signatures...
Unknown signature /var/cache/apt/archives/synaptic_0.57-0.suse093.rb0_i586.rpm: (SHA1) DSA sha1 md5 (GPG) NOT OK (MISSING KEYS: GPG#8c9b4b0d)
E: Error(s) while checking package signatures:
0 unsigned package(s)
1 package(s) with unknown signatures
0 package(s) with illegal/corrupted signatures
E: Handler silently failed

What went wrong?

either edit /etc/apt/apt.conf.d/gpg-check.conf changing "gpg::check true" to "gpg::check no"

or

do a "apt install rpmkey * "

Thanks! The "install rpmkey" didn't work but "/etc/apt..." did.