Internal error: invalid literal for int() with base 10: '' when opening main dashboard

i didn’t notice anything out of the ordinary, the log seems fine:

2022-06-01 18:54:31 - Updating site 'sandsite' from version 2.0.0p23.cre to 2.1.0p1.cre...

 * Installed dir  var/log/agent-receiver
 * Identical new  etc/omd
 * Installed file etc/mk-livestatus/livestatus.socket
 * Updated        etc/mk-livestatus/nagios.cfg
 * Installed file etc/mk-livestatus/livestatus@.service
 * Updated        etc/nagvis/apache.conf
 * Installed link etc/rc.d/10-agent-receiver
 * Updated        etc/nagios/nagios.d/misc.cfg
 * Updated        etc/nagios/conf.d/check_mk_templates.cfg
 * Installed dir  etc/stunnel/conf.d
 * Updated        etc/stunnel/server.conf
 * Installed file etc/stunnel/conf.d/01-livestatus.conf
 * Installed file etc/omd/allocated_ports
 * Updated        etc/ssl/misc/tsget.pl
 * Updated        etc/apache/conf.d/security.conf
 * Updated        etc/apache/conf.d/omd.conf
 * Updated        etc/apache/conf.d/02_fcgid.conf
 * Updated        etc/apache/conf.d/01_wsgi.conf
 * Updated        etc/check_mk/apache.conf
 * Installed file etc/logrotate.d/agent-receiver
 * Installed file etc/logrotate.d/agent-registration
 * Updated        etc/init.d/xinetd
 * Updated        etc/init.d/pnp_gearman_worker
 * Installed file etc/init.d/agent-receiver
 * Updated        etc/init.d/redis
 * Permissions    0755 -> 0775 etc/init.d/mkeventd
 * Updated        etc/init.d/stunnel
 * Vanished       etc/nagios/conf.d/jmx4perl_nagios.cfg
 * Vanished       etc/jmx4perl/config/websphere/threads.cfg
 * Vanished       etc/jmx4perl/config/websphere/appstate.cfg
 * Vanished       etc/jmx4perl/config/websphere/jms.cfg
 * Vanished       etc/jmx4perl/config/websphere/http.cfg
 * Vanished       etc/jmx4perl/config/websphere/jdbc.cfg
 * Vanished       etc/jmx4perl/config/websphere/jca.cfg
 * Vanished       etc/jmx4perl/config/websphere.cfg
 * Vanished       etc/jmx4perl/config/jboss7.cfg
 * Vanished       etc/jmx4perl/config/glassfish.cfg
 * Vanished       etc/jmx4perl/config/tomcat.cfg
 * Vanished       etc/jmx4perl/config/weblogic.cfg
 * Vanished       etc/jmx4perl/config/threads.cfg
 * Vanished       etc/jmx4perl/config/jetty.cfg
 * Vanished       etc/jmx4perl/config/common.cfg
 * Vanished       etc/jmx4perl/config/metrics.cfg
 * Vanished       etc/jmx4perl/config/memory.cfg
 * Vanished       etc/jmx4perl/config/jboss.cfg
 * Vanished       etc/jmx4perl/config/websphere
 * Vanished       etc/jmx4perl/config
 * Vanished       etc/jmx4perl
 * Vanished       .j4p
Creating temporary filesystem /omd/sites/sandsite/tmp...OK
Executing update-pre-hooks script "02_cmk-update-config"...
-| Initializing application...
-| Updating Checkmk configuration...
-| ATTENTION: Some steps may take a long time depending on your installation, e.g. during major upgrades.
-|  1/25 Rewriting password store...
-|  2/25 Migrate Visuals context...
-|  3/25 Migrate dashlets...
-|  4/25 Update global settings...
-|  5/25 Rewriting tags...
-|  6/25 Rewriting hosts and folders...
-|  7/25 Rewriting rulesets...
-| Replacing ruleset non_inline_snmp_hosts with snmp_backend_hosts
-|  8/25 Rewriting autochecks...
-|  9/25 Cleanup version specific caches...
-|  10/25 Migrating fs_used name...
-|  11/25 Migrate pagetype topics...
-|  12/25 Migrate LDAP connections...
-|  13/25 Rewrite BI Configuration...
-| Skipping conversion of bi.mk (already done)
-|  14/25 Set version specific user attributes...
-|  15/25 Rewriting inventory data...
-| Skipping py2 inventory data update (already done)
-|  16/25 Migrate audit log...
-| No audit log present. Skipping.
-|  17/25 Sanitize audit log (Werk #13330)...
-| Skipping (already done)
-|  18/25 Rename discovered host label files...
-|  19/25 Rewriting host, service or contact groups...
-|  20/25 Rewriting notification configuration for ServiceNow...
-|  21/25 Renewing certificates without server name extension...
-| Copied certificate to /omd/sites/sandsite/etc/ssl/sites/sandsite.pem.bak
-| Creating new certificate...
-|  22/25 Adding site CA to trusted CAs...
-|  23/25 Rewrite mknotifyd config for central site...
-|  24/25 Rewriting InfluxDB connections...
-|  25/25 Disabling unsafe EC rules...
-| Done
OK
Executing update-pre-hooks script "01_mkp-disable-outdated"...OK
Updating core configuration...
Finished update.