AVEVA Historian Server 2026 release notes
- Last UpdatedAug 17, 2026
- 7 minute read
- HMI and SCADA
- System Platform
- Historian 2026
AVEVA Historian Server 2026 is a major release.
The AVEVA Historian Server release notes describe applicable expectations and limitations, new features and enhancements, fixed and known issues, and documentation included in this release for Historian Server applications, including Historian Client Web.
Expectations and limitations
The following expectations and deprecated features should be considered for this release of AVEVA Historian Server:
Replication to CDS through OCMC
Starting with Historian 2026, the ability to configure new CONNECT Data Services (CDS) replications through the Operations Control Management Console (OCMC) has been deprecated.
Impact:
-
Existing CDS replication configurations will continue to function as expected
-
New CDS replication setups cannot be configured through OCMC
-
This feature will be fully removed in a future release
Recommended Action: Customers requiring cloud replication functionality should migrate to Historian Agent, which provides enhanced capabilities and ongoing support for cloud data connectivity.
For assistance with migration, please contact AVEVA Support.
Deprecation of legacy HCAP architecture
The Historian Client Access Point (HCAP) architecture has been modernized to use gRPC Remote Procedure Calls (gRPC), a higher performance framework that offers improved startup time, scalability, and maintainability. gRPC communicates over TCP/IP port 32565.
Impact: In most environments, this change has no functional impact and provides improved performance. However, during node-by-node upgrades, Historian data retrieval from non-upgraded nodes will not be accessible until all nodes are upgraded to Historian 2026.
Recommended Action: If required, you can temporarily revert to the previous version of HCAP using the Windows services management console:
-
In the Windows Search bar, type Services.
-
Right-click the Services icon and select Run as Administrator.
-
Select Yes to allow the app to make changes on your system.
-
In the Services (Local) window of the Services app, scroll down and select AVEVA Historian Client Access Point (Classic).
-
Select Start the Service.
This option will be removed in the next major release of Historian. Update any legacy software to a supported interface as soon as possible.
Deprecation of Historian Client Web Classic
The Classic version of Historian Client Web is deprecated. Historian Client Web Modern is now the only supported version.
Impact
-
Setups that used the Classic interface automatically migrate to the Modern interface.
-
The transition is expected to be seamless.
-
In some cases, dashboards might require reconfiguration.
Recommended Action: If required, reconfigure any objects that do not show the expected data.
Effect of changing SMS configuration on the Historian license certificate
If you change the System Management Server (SMS) to No System Management Server configured after you have configured Historian, the service aahClientAccessPointNG fails to start and logs: Certificate with thumbprint <hash> does not exist in the certificate store.
This is because the Historian Gateway HTTPS port was previously bound to the SMS-issued certificate. When SMS is removed, that certificate is no longer present in the local certificate store, and aahClientAccessPointNG has no usable certificate to load.
New features and enhancements
AVEVA Historian Server 2026 applications include the following features and enhancements.
Enhanced silent installation TLS support
Silent installation and configuration now supports Transport Layer Security (TLS) 1.3 (See System Platform Installation for more information on silent installation)
Improved authentication to CONNECT
Authenticating to CONNECT is faster and more reliable.
Redundant SSO capability added
RSSO has been added as a fallback mode.
HCAP architecture updated
Historian Client Access Point (HCAP) architecture updated to use gRPC (see Expectations and limitations for additional information)
Historian Client Web Modern updated to .NET 10 framework
Historian Client Web is updated to use the .NET framework. Users can now update the .NET framework independently from the application
Historian Client Web browse content page enhanced
The Historian Client Web browse content page has been updated to the style of the browse content page of Insight.
Historian Client Web internal search engine improved
Historian Client Web now uses Lucent for its internal search engine instead of Elastic.
OleDB upgraded to 19.4.1
The Object Linking and Embedding Database (OleDB) has been upgraded to version 19.4.1
Resolved issues
The following items were resolved with this release:
|
Defect ID |
Case Number |
Description |
|---|---|---|
|
2906914 |
960343330 |
High SQL Server memory consumption slowed down Historian queries. |
|
2968797 |
960365321 |
Insight Publisher did not correctly publish values from InTouch 2023. |
|
2895591 |
960355209 |
Auto Summary data would stall during backfill. |
|
2997831 |
960372728 |
Wrong timezone was displayed for analog tag queries. |
|
3061742 |
960389860 |
Historian Client Web: cyber security vulnerability discovered. |
|
3103049 |
960386536 |
Could not edit username and password fields in IDAS Configurator. |
|
2996548 |
960373266 |
Tag imported incremented values by one for MaxEu and MAXRAW during full import. |
|
3029223 |
960381994 |
ConfigStatusPending Table was overrunning the INT size on the table identity. |
|
2982098 |
960370481 |
Changing Data and Log paths in Configurator Search tab would fail even though aahSearchIndexer service was running. |
|
3238886 |
960399586 |
Running an Average retrieval query against any tag that had an OPCQuality of 1276 failed. |
|
3289466 |
960410095 |
Querying [Runtime].[dbo].[StringHistory] would not return accurate results. |
|
3370555 |
960427029 |
UOM function was unable to convert seconds to minutes. |
|
3387012 |
960428663 |
The Duration function and the TOTAL function, when applied to the same data, returned different date-time values. |
|
3474195 |
960421198 |
Backfill from T1 to T2 servers stalled for three hours and never finished. |
|
3454758 |
960444421 |
Warning observed in SMC of T1 machine: "Main Replication failed add non-streamed value to HCAL." |
|
3700864 |
960522676 |
Size of PublicNameSpace table increased from 5GB to 20GB within minutes of reboot. |
|
3680926 |
960506888 |
Query performance was degraded for queries using Auto Summary. |
|
3668740 |
960509777 |
Historian Client Web Modern: Aggregation Type "Hourly" only returned one record regardless of the period. |
|
3729227 |
960515758 |
Changes to tag descriptions did not propagate to T2 Historian. |
|
3680540 |
960497503 |
Historian Configuration Service crashed a few days after a fresh start. |
|
3708002 |
960531812 |
Could not import LGH files from InTouch HMI. |
|
3769882 |
960549245 |
aahOleDB crashed with Historian 2023 R2 P01 and Historian 2023 R2 SP1. |
|
3824648 |
960497840 |
Intermittent failover historizing data using warm-redundancy engines from App Server. |
|
4046176 |
960631040 |
Bad/Null values were not handled correctly when replicating to PI Historian. |
|
4233219 |
960658717 |
T2 server failed to create GWh unit because process was deadlocked. |
|
3999081 |
960607869 |
Historian lost license while running due to TCP port exhaustion. |
|
4326426 |
960622683 |
Logger spammed by errors from aahMetaDataServer after upgrade to 2023 R2 SP1 P02. |
|
4526022 |
962626739 |
Not clearing child tables before deleting parent table EventHistory resulted in error messages. |
|
4544670 |
962722341 |
Inconsistent SQL query results could occur in 2023 R2 SP1 P03. |
|
4600670 |
962757303 |
SQL/Main Metadata Server COM error caught converting the Timestamp data type to Numeric. |
|
4426801 |
962684686 |
An aahStorage VTQ count of 1000 would result in an error. |
|
4497189 |
962703941 |
All services were running but Historian was stopped after migration to 2023 R2 SP1 P03. |
|
4374452 |
962638909 |
Historical Data Access in OMI Web Client was unauthorized through a nested domain group. |
|
3309400 |
960410783 |
Historian Client Web: when using a tag name in the URL, "The content couldn't be saved" message appeared. |
|
3258436 |
960396124 |
VBA Runtime-error would result when changing from Windows to SQL authentication. |
|
3389843 |
960430160 |
Historian Client Web: any content could be removed by anyone in All Content list. |
|
3543465 |
960465004 |
TagFilter parameter did not respect filter conditions when requesting more tags using Historian Data REST API. |
|
3550856 |
960469900 |
Generating an Alarm would result in Null values in the AlarmDuration column in the dbo.Event table. |
|
3028192 |
960381805 |
Historian Client Web: Changing license mode from Connected Experience resulted in LicenseHelper exception. |
|
3203415 |
960396445 |
Historian Client Web: Location did not appear in Link to Asset field. |
|
3188323 |
960387013 |
Historian Client Web: The line chart on the dashboard would change to a column chart for shared links. |
|
3256327 |
960402948 |
Historian Client Web would hang when clicking on trend graph symbol. |
|
3650810 |
960504900 |
Historian Client Web Comment window froze after viewing or creating a comment. |
|
3692435 |
960524011 |
Historian Configuration Service crashed randomly. |
|
3302062 |
960412988 |
Historian Configurator parsed domain name when adding a user to Historian. |
|
3770292 |
960551178 |
Historian Client Web Alarm page would be empty until moving the scroll bar. |
|
3851701 |
960564782 |
Historian Client Web: Saving another user's dashboard changed ownership. |
|
4230460 |
960655104 |
Historian Client Web license manager displayed two licenses in use from the same user. |
|
4287281 |
962469203 |
Historian Client Web saved contents disappeared after clicking on Show Contents. |
|
4290926 |
960665492 |
Historian Client Web InAlarm displayed 0NaN:0NaN:0NaN. |
|
4756231 |
962810301 |
Tag importer wizard stopped responding during import. |
|
4779503 |
962828011 |
After upgrading to 2023 R2 SP1 Patch 04 some queries stopped working. |
|
4772172 |
962823859 |
Historian Client Web: performance degraded when switching the Y-axis type to Multiple. |
|
4756398 |
962806380 |
QD24 data points skipped when replicating to CONNECT. |
|
4793463 |
962823361 |
App crashed aahClientAccessPointNG.exe on all the AOS nodes. |
|
4749814 |
962797874 |
Historian Client Web: trends would appear flat when too many tags were selected over too long a time period. |
Known issues
No Historian Server application issues have been identified in this release.
User Documentation
Notice – Online help access: AVEVA Historian 2026 does not include online help files or the AVEVA Help Viewer.
Context-sensitive help calls now open the corresponding content on docs.aveva.com.
If internet access is not available, selecting a help link displays a QR code that
you can scan with an internet-connected mobile device to open the help content.
All product documentation is still available in PDF format on the installation media,
and is installed locally when you install System Platform.
The following user documentation is included in this release:
-
Historian Client Web online help – Explains how you can use AVEVA Historian Client Web to view, explore, and interact with Historian data through a browser-based interface, including creating and managing content. Access to this help is available by selecting the Help (question mark) icon in the top right of the browser window when using Historian Client Web.
-
Historian Server Administrator online help – Explains how you can use AVEVA Historian to administer, configure, replicate to, and maintain Historian servers, including setting up data collection, managing security, and monitoring system performance. Access to this help is available by pressing F1 when using Historian.
-
Single user guides in PDF form (included as part of the install):
-
AVEVA Historian Client Web. Explains how to interact with Historian data using a browser-based interface.
-
AVEVA Historian Administrator Guide. Explains configuring and administrating Historian.
-
AVEVA Historian Concepts Guide. Explains the fundamentals of data storage and retrieval used by Historian and Historian Client applications.
-
AVEVA Historian Database Guide. Explains in detail all Historian database details, such as tables, views, and stored procedures.
-
AVEVA Historian Retrieval Guide. Explains the retrieval modes and options available for accessing stored data.
-
AVEVA Historian Scenarios Guide. Describes how to configure Historian for use in specific, real-world scenarios and use cases.
-