diff --git a/admin-guide/troubleshooting/deployment.rst b/admin-guide/troubleshooting/deployment.rst
index d36d820e..29fca094 100644
--- a/admin-guide/troubleshooting/deployment.rst
+++ b/admin-guide/troubleshooting/deployment.rst
@@ -97,3 +97,16 @@ If the AD join seams to be broken (failed logins, etc.), then the node can be au
 
 - remove ``/etc/krb5.keytab``
 - run puppet, e.g. with ``puppet agent --test``
+
+
+Cannot Load YFS Kernel Module
+=============================
+
+If the ``yfs-client`` does not start due to "key not available" ::
+
+    Sep 02 13:21:34 pc12661.psi.ch systemd[1]: Starting AuriStorFS Client Service...
+    Sep 02 13:21:34 pc12661.psi.ch modprobe[29282]: modprobe: ERROR: could not insert 'yfs': Required key not available
+
+then there is most probably SecureBoot blocking the loading of the unsigned ``yfs`` kernel module.
+
+Please disable secure boot in the BIOS/firmware settings.