If you're having pveproxy issues after adding a node back to a cluster which uses self-signed certificates, such as;
pveproxy: /etc/pve/local/pve-ssl.pem: failed to use local certificate chain (cert_file or cert) at /usr/share/perl5/PVE/APIServer/AnyEvent.pm line 1903.
CA certificate and CA private key do not match
Can't open /tmp/pvesslconf-507419.tmp for reading, No such file or directory
140633868483456:error:02001002:system library:fopen:No such file or directory:../crypto/bio/bss_file.c:69:fopen('/tmp/pvesslconf-507419.tmp','r')
140633868483456:error:2006D080:BIO routines:BIO_new_file:no such file:../crypto/bio/bss_file.c:76:
Try removing the SSL certificates on your Clustered nodes and regenerating them with the following commands;
rm -f /etc/pve/pve-root-ca.pem /etc/pve/priv/pve-root-ca.* /etc/pve/local/pve-ssl.*;
pvecm updatecerts -f;