Tekla Structures Open API – Bug Reports

 Tekla Structures Open API – Bug Reports, Limitations & Practical Workarounds

Overview

While developing advanced automation tools using the Tekla Structures Open API, I encountered several undocumented limitations and inconsistent behaviors, particularly within the Drawing API.

This page documents confirmed Tekla API issues, official responses from Tekla Open API experts, and production-ready workaround approaches implemented during real projects.

All issues listed below were reproduced, validated, and acknowledged by Tekla, with corresponding maintenance Jira tickets raised where applicable.

1. GA Drawing – 3D View Creation Limitation Issue

The Create3DView method does not work for General Arrangement (GA) drawings, although it is available in the API documentation.

Observation

Method executes without error

No 3D view is generated in GA drawings

Works only for non-GA drawing contexts

Official Confirmation

Tekla Open API support confirmed this as a known limitation.

Maintenance Ticket: TTSD-69750

Priority: High

Status: Acknowledged by Tekla Development Team

Impact

Automation tools relying on programmatic 3D view generation must avoid GA drawings or apply alternate workflows.

2. Drawing Object Bounding Box Returns Zero Values

Affected Objects

Straight Dimensions

Section Marks

Detail Marks

Some Drawing Tags

Issue

GetAxisAlignedBoundingBox() returns zero values for the above drawing objects.

Working Objects

Text objects return valid bounding box values

Official Confirmation

This behavior was confirmed as a Tekla API bug.

Maintenance Ticket: TTSD-11114

Impact

Bounding-box–based automation (clash detection, highlighting, overlays) fails for these drawing objects.

3.Numeric UDA Update Issue in Tekla Structures 2020

Issue Description

While using the Tekla Open API to get and set User-Defined Attribute (UDA) values, an issue was observed in Tekla Structures 2020 where numeric UDA values cannot be updated once they are set via the API.

Observed Behavior

A numeric UDA value (e.g., INTEGER, DOUBLE) is successfully assigned using the API.

Subsequent attempts to modify or overwrite the same numeric UDA value via the API fail.

No exception or error is thrown, but the value remains unchanged.

This behavior is consistent across repeated tests.

Expected Behavior

Numeric UDA values should be modifiable multiple times via the API, similar to string-based UDAs.

Scope & Version Impact

Affected Version: Tekla Structures 2020

Tested Versions: 2020, 2023

Result:

Issue reproducible only in Tekla Structures 2020

Works as expected in newer versions

Official Response

The issue was reviewed by Tekla Open API support and confirmed as a version-specific limitation.

Fixes implemented in newer Tekla versions are not backported to older releases such as 2020.

Impact on Automation

Automation tools relying on numeric UDA updates may behave incorrectly in Tekla Structures 2020.

Developers must apply alternative logic or version checks when supporting older Tekla environments.

Recommended Workaround

Use string-type UDAs where frequent updates are required.

Implement version-based conditional logic to avoid numeric UDA overwrites in Tekla Structures 2020.

Encourage migration to newer Tekla versions for full API reliability.

3.Numeric UDA Update Issue in Tekla Structures 2020

Issue Description

While using the Tekla Open API to get and set User-Defined Attribute (UDA) values, an issue was observed in Tekla Structures 2020 where numeric UDA values cannot be updated once they are set via the API.

Observed Behavior

A numeric UDA value (e.g., INTEGER, DOUBLE) is successfully assigned using the API.

Subsequent attempts to modify or overwrite the same numeric UDA value via the API fail.

No exception or error is thrown, but the value remains unchanged.

This behavior is consistent across repeated tests.

Expected Behavior

Numeric UDA values should be modifiable multiple times via the API, similar to string-based UDAs.

Scope & Version Impact

Affected Version: Tekla Structures 2020

Tested Versions: 2020, 2023

Result:

Issue reproducible only in Tekla Structures 2020

Works as expected in newer versions

Official Response

The issue was reviewed by Tekla Open API support and confirmed as a version-specific limitation.

Fixes implemented in newer Tekla versions are not backported to older releases such as 2020.

Impact on Automation

Automation tools relying on numeric UDA updates may behave incorrectly in Tekla Structures 2020.

Developers must apply alternative logic or version checks when supporting older Tekla environments.

Recommended Workaround

Use string-type UDAs where frequent updates are required.

Implement version-based conditional logic to avoid numeric UDA overwrites in Tekla Structures 2020.

Encourage migration to newer Tekla versions for full API reliability.

Conclusion

These findings highlight that while Tekla Open API is powerful, real-world automation requires deep testing, validation, and workaround strategies.

Through structured debugging, forum collaboration, and direct interaction with Tekla Open API specialists, these issues were:

Identified

Reproduced

Officially acknowledged

Mitigated using stable alternatives

About the Author

Balaji T

Tekla Structures | Tekla Open API Developer

Structural Automation Engineer

3.9+ years in steel detailing and automation

Advanced Tekla Open API & C# .NET developer

Active Tekla Developer Forum contributor

Focused on production-grade BIM automation