UnresolvedAssemblyError when using Expandable Row Editing and Local Action

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MarijeSchillern

Member since 2012

110 posts

MOD

Posted: 6 days 9 hours ago

Last activity: 6 days 9 hours ago

Posted: 17 Jul 2026 7:23 EDT
Last activity: 17 Jul 2026 7:23 EDT

UnresolvedAssemblyError when using Expandable Row Editing and Local Action

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Issue

Tables using Expandable row editing in conjunction with other Local Actions cause performance and UI issues.

Symptoms and Impact

When a Master-Detail configuration uses expandable row editing and allows row updates through a Local Action (modal dialog), users may encounter runtime errors, screen freezes, or unexpected behavior while editing rows.

Typical symptoms: The screen becomes unresponsive during row updates.

Error

com.pega.pegarules.pub.PRRuntimeError: PRRuntimeError 
    at com.pega.pegarules.session.internal.mgmt.base.ThreadRunner.runActivitiesAlt(ThreadRunner.java:721) 

Caused by: com.pega.pegarules.pub.generator.UnresolvedAssemblyError: Failed to find instance @baseclass.pyUpdateRTEContent 
    at com.pega.platform.executionengine.vtable.internal.RuleDispatcherImpl.resolveModels(RuleDispatcherImpl.java:486) 

Caused by: com.pega.pegarules.pub.generator.RuleNotFoundException: Failed to find a 'RULE-OBJ-MODEL' with the name 'PYUPDATERTECONTENT' that applies to '@baseclass'.

Steps to Reproduce

To reproduce this issue, complete the following steps:

In Dev Studio, create a Grid layout.

In the Row operations section, enable Master-Detail.

Under Display of details, select Expandable rows.

Configure a Screen Layout for the Flow Action.

In the Rich Text Editor (RTE) used in the Email Reply local action, enable Spell Checker.

Save the configuration and launch the application.

Navigate to a row in the Master-Detail grid.

Click Reply to open the Email Reply editor.

Enter text containing a spelling error.

Open the Spell Checker and select one of the suggested corrections.

Click outside the suggestions popup. Result: An error dialog is displayed, and the spell checker cannot continue. The reply editor loses its context (ReplyMetaData page/Class context), causing the operation to fail.

Root Cause

The issue occurs due to a product limitation when the following configuration is used together:

Master-Detail grid

Expandable Rows

Email Reply Local Action with Rich Text Editor (Spell Checker)

This combination causes the reply editor to lose its context after a spell-check replacement, leading to the observed error.

Solution

Local Change

To work around this issue, complete the following steps:

On the Operations tab ️of the table layout, in the Row editing type list, select None.

In the Grid operations section, select Show details.

In the Detail Flow Action field, enter the name of the Flow Action that is displayed when the row is expanded.

Select the Display an expand/collapse icon per row checkbox.

Resolution

To avoid editing context collisions and unsupported behavior, use only one editing approach for a given row:

Option 1: Use expandable row editing.

Option 2: Use a Local Action that opens a modal dialog.

Do not combine both editing methods on the same page or within the same user interaction flow. Using a single editing mechanism prevents processing context conflicts and avoids parameter overrides that can lead to errors and screen freezes.