Workflow Engine 21.1.2

June 18, 2026

Overview

Workflow Engine 21.1.2 is a targeted hotfix release focused on relational database migration coverage for CalendarName, native ASP.NET Core OpenAPI generation in Workflow Engine Web API, and BPMN import stability in Workflow Designer.

Why update

• Fix missing WorkflowProcessInstance.CalendarName columns in upgraded relational databases so scheme updates continue to work correctly on older installations.
• Restore native ASP.NET Core OpenAPI document generation when you expose Workflow Engine Web API endpoints through AddOpenApi().
• Fix the Workflow Designer Upload BPMN dialog so BPMN imports no longer fail with a client-side designer is not defined error.

Key features

• Added follow-up migrations for MSSQL, MySQL, PostgreSQL, SQLite, and Oracle to create the missing CalendarName column in existing WorkflowProcessInstance tables when needed.
• Native ASP.NET Core OpenAPI generation now works for Workflow Engine Web API bulk RPC endpoints without throwing JSON schema export exceptions.
• Workflow Designer BPMN import now initializes the upload dialog against the active graph safely, restoring the Upload BPMN flow.

Changelog

Update instructions

• All packages: update Workflow Engine packages to version 21.1.2.
• If you use MSSQL, MySQL, PostgreSQL, SQLite, or Oracle persistence and your database was created before the CalendarName column was originally introduced, run Workflow Engine migrations after upgrading so the missing WorkflowProcessInstance.CalendarName column is added.
• If you use Workflow Engine Web API with native ASP.NET Core OpenAPI generation via AddOpenApi(), update to 21.1.2 to avoid schema generation failures.
• If you use BPMN import in Workflow Designer, update your Designer assets or packages to 21.1.2 to restore the Upload BPMN dialog behavior.
• No additional migration steps are required for MongoDB or for installations that already contain the CalendarName column.

Bug fixes

• Persistence providers: added new migrations for MSSQL, MySQL, PostgreSQL, SQLite, and Oracle to create the missing CalendarName column in WorkflowProcessInstance when upgrading databases that predate the original column addition.
• Web API: fixed native ASP.NET Core OpenAPI generation for Workflow Engine endpoints registered through AddOpenApi(). Bulk RPC response models with nullable boolean results no longer trigger System.Text.Json.JsonException during schema export.
• Designer: fixed BPMN import dialog initialization so the Upload BPMN flow no longer references an undefined designer object on the client.

Resources

• Database migrations guide: Database versioning.
• Web API OpenAPI documentation: OpenAPI.
• BPMN plugin setup and import flow: Using BPMN plugin.