Introduction
Direct DOM manipulation in ServiceNow client scripts can lead to maintainability issues, especially after instance upgrades. Modifying out-of-box UI elements can cause unexpected behavior, broken functionality, or script errors due to changes in ServiceNow’s underlying structure. Instead, using the GlideForm API (g_form) ensures compatibility, stability, and easier maintenance of client-side customizations.
Resolution Steps
1. Search for scripts that use document.getElementById(), querySelector(), or jQuery ($()) to modify the ServiceNow UI.
2. Replace DOM Manipulation with GlideForm API. Use g_form methods to interact with form elements instead of modifying the DOM directly.
3. Test and validate scripts in a sub-production instance and check UI behavior after ServiceNow upgrades to ensure functionality.
Before:

After:

By removing direct DOM manipulation and using the GlideForm API, client scripts become more maintainable, upgrade-safe, and stable. This approach prevents unexpected UI failures and ensures scripts continue functioning across ServiceNow updates.
For more detailed guidance on resolving this issue, please contact us at support@dt-advisory.ch.