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- Getting Started
- Setup and Configuration
- Automation Projects
- Dependencies
- Types of Workflows
- Control Flow
- File Comparison
- Automation Best Practices
- Source Control Integration
- Debugging
- Logging
- The Diagnostic Tool
- Workflow Analyzer
- About Workflow Analyzer
- ST-NMG-001 - Variables Naming Convention
- ST-NMG-002 - Arguments Naming Convention
- ST-NMG-004 - Display Name Duplication
- ST-NMG-005 - Variable Overrides Variable
- ST-NMG-006 - Variable Overrides Argument
- ST-NMG-008 - Variable Length Exceeded
- ST-NMG-009 - Prefix Datatable Variables
- ST-NMG-011 - Prefix Datatable Arguments
- ST-NMG-012 - Argument Default Values
- ST-NMG-016 - Argument Length Exceeded
- ST-NMG-017 - Class name matches default namespace
- ST-DBP-002 - High Arguments Count
- ST-DBP-003 - Empty Catch Block
- ST-DBP-007 - Multiple Flowchart Layers
- ST-DPB-010 - Multiple instances of [Workflow] or [Test Case]
- ST-DBP-020 - Undefined Output Properties
- ST-DBP-021 - Hardcoded Timeout
- ST-DBP-023 - Empty Workflow
- ST-DBP-024 - Persistence Activity Check
- ST-DBP-025 - Variables Serialization Prerequisite
- ST-DBP-027 - Persistence Best Practice
- ST-DBP-028 - Arguments Serialization Prerequisite
- ST-USG-005 - Hardcoded Activity Properties
- ST-USG-009 - Unused Variables
- ST-USG-010 - Unused Dependencies
- ST-USG-014 - Package Restrictions
- ST-USG-017 - Invalid parameter modifier
- ST-USG-020 - Minimum Log Messages
- ST-USG-024 - Unused Saved for Later
- ST-USG-025 - Saved Value Misuse
- ST-USG-026 - Activity Restrictions
- ST-USG-027 - Required Packages
- ST-USG-028 - Restrict Invoke File Templates
- ST-USG-032 - Required Tags
- ST-USG-034 - Automation Hub URL
- Variables
- Arguments
- Imported Namespaces
- Coded automations
- Introduction
- Registering custom services
- Before and After contexts
- Generating code
- Generating coded test case from manual test cases
- Troubleshooting
- Trigger-based Attended Automation
- Object Repository
- The ScreenScrapeJavaSupport Tool
- Extensions
- About extensions
- SetupExtensions tool
- UiPathRemoteRuntime.exe is not running in the remote session
- UiPath Remote Runtime blocks Citrix session from being closed
- UiPath Remote Runtime causes memory leak
- UiPath.UIAutomation.Activities package and UiPath Remote Runtime versions mismatch
- The required UiPath extension is not installed on the remote machine
- Screen resolution settings
- Group Policies
- Cannot communicate with the browser
- Chrome extension is removed automatically
- The extension may have been corrupted
- Check if the extension for Chrome is installed and enabled
- Check if ChromeNativeMessaging.exe is running
- Check if ComSpec variable is defined correctly
- Enable access to file URLs and Incognito mode
- Multiple browser profiles
- Group Policy conflict
- Known issues specific to MV3 extensions
- List of extensions for Chrome
- Chrome Extension on Mac
- Group Policies
- Cannot communicate with the browser
- Edge extension is removed automatically
- The extension may have been corrupted
- Check if the Extension for Microsoft Edge is installed and enabled
- Check if ChromeNativeMessaging.exe is running
- Check if ComSpec variable is defined correctly
- Enable access to file URLs and InPrivate mode
- Multiple browser profiles
- Group Policy conflict
- Known issues specific to MV3 extensions
- List of extensions for Edge
- Extension for Safari
- Extension for VMware Horizon
- Extension for Amazon WorkSpaces
- SAP Solution Manager plugin
- Excel Add-in
- Studio testing
- Troubleshooting
- About troubleshooting
- Assembly compilation errors
- Microsoft App-V support and limitations
- Internet Explorer X64 troubleshooting
- Microsoft Office issues
- Identifying UI elements in PDF with Accessibility options
- Repairing Active Accessibility support
- Validation of large Windows-legacy projects takes longer than expected
Studio user guide
Last updated Mar 4, 2026
ST-USG-017 - Invalid parameter modifier
Rule ID: ST-USG-017
Scope: Coded workflow
Description
When the Execute() entry method contains out or ref parameters, an error is shown.
Recommendation
Avoid declaring out and ref parameters for the Execute() entry method, such as in the following example:
public void Execute(ref string location, out string country)
public void Execute(ref string location, out string country)