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

same problem when I’m opening the builtin dashboard “Windows hosts” with the graphs

“cpu: processor queue averages”,
“Disks: Wait time” and
“Disks: Queue lengths”

Problem while rendering dashboard element 4 of type combined_graph: Failed to calculate a graph recipe… Have a look at var/log/web.log for further information.

Problem while rendering dashboard element 5 of type combined_graph: Failed to calculate a graph recipe… Have a look at var/log/web.log for further information.

Problem while rendering dashboard element 10 of type combined_graph: Failed to calculate a graph recipe… Have a look at var/log/web.log for further information.

after update from 2.0.0p20.cee to 2.0.0p29.cee and after this update to 2.1.0p16.cee.

tail -n 70 ~/var/log/update.log
	OMD[mycmk]:~$ tail -n 70 ~/var/log/update.log
	 * Vanished       etc/jmx4perl
	 * Vanished       .j4p
	Creating temporary filesystem /omd/sites/mycmk/tmp...OK
	Executing update-pre-hooks script "01_mkp-disable-outdated"...OK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.
	-|  1/28 Rewriting password store...
	-|  2/28 Migrate Visuals context...
	-|  3/28 Update global settings...
	-|  4/28 Rewriting tags...
	-|  5/28 Rewriting hosts and folders...
	-|  6/28 Rewriting rulesets...
	-| Found deprecated ruleset: non_inline_snmp_hosts
	-| Replacing ruleset non_inline_snmp_hosts with snmp_backend_hosts
	-|  WARN: Service condition in rule looks like an absolute windows path that is not correctly escaped.
	-|  Use double backslash as directory separator in regex expressions, e.g.
	-|  'C:\\Program Files\\'
	-|  (Ruleset: checkgroup_parameters:fileinfo, Folder: server-2/server_agent/server_baked-agents, Rule nr: 0, Condition:C:\\Windows\\System32\\LMUD1Plang\.dll$)
	-|  WARN: Service condition in rule looks like an absolute windows path that is not correctly escaped.
	-|  Use double backslash as directory separator in regex expressions, e.g.
	-|  'C:\\Program Files\\'
	-|  (Ruleset: checkgroup_parameters:fileinfo, Folder: server-2/server_agent/server_baked-agents, Rule nr: 1, Condition:C:\\Windows\\System32\\LMUD1Olang\.dll$)
	-|  WARN: Service condition in rule looks like an absolute windows path that is not correctly escaped.
	-|  Use double backslash as directory separator in regex expressions, e.g.
	-|  'C:\\Program Files\\'
	-|  (Ruleset: checkgroup_parameters:fileinfo, Folder: server-2/server_agent/server_baked-agents, Rule nr: 1, Condition:C:\\Windows\\System32\\LMUD1Plang\.dll$)
	-|  WARNING: Invalid rule configuration detected (Ruleset: special_agents:ipmi_sensors, Title: IPMI Sensors via Freeipmi or IPMItool, Folder: server-2,
	-| Rule nr: 1, Exception: The selected element '%r' is not longer available. Please select something else.)
	-|  Detected 1 issue(s) in configured rules.
	-| To correct these issues, we recommend to open the affected rules in the GUI.
	-| Upon attempting to save them, any problematic fields will be highlighted.
	-|  7/28 Rewriting discovered host labels...
	-|  8/28 Rewriting autochecks...
	-|  9/28 Cleanup version specific caches...
	-|  10/28 Migrating fs_used name...
	-|  11/28 Migrate pagetype topics...
	-|  12/28 Migrate dashlets...
	-|  13/28 Migrate LDAP connections...
	-|  14/28 Rewrite BI Configuration...
	-| Skipping conversion of bi.mk (already done)
	-|  15/28 Set version specific user attributes...
	-|  16/28 Check for insecure password hashes, enforce password reset...
	-|  Users with insecure password hashes have been found in the htpasswd file. These users will be required to change their password on their next login.
	-| Please ensure that the affected users log in and change their password before updating to Checkmk version 2.2. Otherwise these users will not be able to log in anymore and their passwords will need to be reset manually by an administrator (either the user configuration or via the cmk-passwd command).
	-| The following users are affected:
	-| cmkadmin
	-|  17/28 Rewriting inventory data...
	-| Skipping py2 inventory data update (already done)
	-|  18/28 Migrate audit log...
	-| New audit log already existing. Skipping.
	-|  19/28 Sanitize audit log (Werk #13330)...
	-| Skipping (already done)
	-|  20/28 Rename discovered host label files...
	-|  21/28 Rewriting host, service or contact groups...
	-|  22/28 Rewriting notification configuration for ServiceNow...
	-|  23/28 Renewing certificates without server name extension...
	-| Copied certificate to /omd/sites/mycmk/etc/ssl/sites/mycmk.pem.bak
	-| Creating new certificate...
	-|  24/28 Adding site CA to trusted CAs...
	-|  25/28 Rewrite mknotifyd config for central site...
	-|  26/28 Rewriting InfluxDB connections...
	-|  27/28 Disabling unsafe EC rules...
	-|  28/28 Update bakery links and settings...
	-| Done
	OK
	Updating core configuration...
	Finished update.