Troubleshooting Common Issues in List Filter Plus Web PartList Filter Plus Web Part is a powerful tool for enhancing SharePoint list and library filtering, but like any component it can run into issues. This article walks through common problems, diagnostic steps, and practical fixes to get your filters working reliably.
1. Symptoms and initial checks
Start with basic verification to reduce scope quickly:
- Confirm compatibility: Ensure the List Filter Plus version matches your SharePoint environment (on-premises vs SharePoint Online, specific SharePoint version).
- Browser test: Reproduce the issue in multiple browsers (Edge, Chrome, Firefox). Disable browser extensions and test in a private/incognito window.
- Permissions: Verify the user has at least Read access to the target list/library and any data sources used by the web part.
- Page and web part health: Edit the page and check web part settings. Look for visible configuration errors or missing required fields.
- Console errors: Open browser developer tools (F12) → Console to capture JavaScript errors shown when the page loads or when interacting with the web part.
- Network activity: Use the Network tab to see failed requests, long-running queries, or blocked resources.
2. Common issue: Web part not displaying or appearing blank
Causes & fixes:
- Corrupt configuration or missing required settings:
- Re-open the web part settings and re-save them. If unsure, reset to defaults and reconfigure.
- Missing or blocked script resources:
- Check that referenced CSS/JS URLs are accessible. Ensure CDN or local script libraries aren’t blocked by Content Security Policy (CSP) or by mixed-content (HTTP vs HTTPS) issues.
- Permission restrictions:
- Confirm the current user can access the source list/library and any connector sources. Some web parts hide content for insufficient permissions.
- Page rendering conflicts:
- Temporarily remove other third-party web parts from the page to identify conflicts.
3. Common issue: Filters not returning expected results
Possible causes:
- Wrong column internal names or data types:
- Use the list settings to confirm internal column names and data types (choice, lookup, person, managed metadata). Filter configuration must match those types.
- Value formatting differences:
- Dates, times, and number formatted values may not match the filter criteria (time zone differences or localization formatting).
- Lookup and managed metadata issues:
- For lookup fields, ensure the filter references the lookup ID or the lookup value as required by the web part configuration.
- Caching or indexing delays:
- If results rely on search indexing, allow time for the indexer to update. Clear web part/client cache if needed.
Fix steps:
- Reconfigure the filter mapping: explicitly select the column using its internal name or pick from the web part’s column picker.
- Test with a simple filter (single text field) to confirm core filtering works, then gradually reintroduce complex fields.
- Convert date/time filters to use standardized values (UTC) if timezone mismatches are suspected.
4. Common issue: Performance slowness with large lists
Why it happens:
- SharePoint list throttling and large dataset queries can slow filter responses.
- Excessive client-side filtering or retrieving many columns and rows.
- Inefficient filter queries that don’t leverage indexed columns.
Remedies:
- Use indexed columns on lists for fields commonly used in filters.
- Limit the number of returned columns—request only what the web part needs.
- Implement server-side or search-driven filtering if supported (use the Search API or CAML queries optimized for indexes).
- Enable pagination or restrict the initial result set.
- Monitor ULS logs (on-prem) or SharePoint Online throttling messages to identify throttling events.
5. Common issue: JavaScript errors and conflicts
Signs: Console shows errors like undefined functions, missing libraries, or conflicting script names.
Troubleshooting:
- Identify the error stack in the browser console and trace which file or function triggers it.
- Confirm required libraries (e.g., jQuery) are loaded before the web part scripts. Avoid multiple versions of the same library.
- Use non-conflict patterns (e.g., jQuery.noConflict()) if multiple scripts require different jQuery versions.
- Isolate the web part on a clean page to reproduce the error without other custom scripts.
6. Common issue: Styling and layout problems
Causes:
- CSS conflicts with the page theme or other web parts.
- Responsive behavior differences across browsers.
- Custom master page or CSS overrides that affect web part selectors.
Fixes:
- Inspect computed styles in the browser dev tools to find overriding rules.
- Use more specific CSS selectors in customizations or wrap the web part in a container with unique class names.
- If the web part supports custom CSS classes, apply a dedicated wrapper class to scope styles.
7. Common issue: Filter values not persisting or state lost on postback
Symptoms: Selected filter resets after page refresh or navigation.
Causes & fixes:
- Session/state handling: Ensure the web part is configured to persist filter state (some web parts offer URL-parameter persistence or cookies/localStorage options).
- Page or web part caching: If page output caching is enabled, it may serve a cached page without current filter state. Disable or configure caching to respect dynamic filters.
- URL rewriting: Confirm custom redirects or URL rewrites aren’t removing query string parameters used for filter state.
8. Troubleshooting tools and logs
- Browser Developer Tools (Console, Network, Performance)
- Fiddler or Wireshark for network-level inspection
- ULS logs (SharePoint on-premises) for server-side exceptions
- SharePoint Audit logs and usage analytics (SharePoint Online)
- Web part-specific logging (if the vendor provides logs or diagnostic modes)
9. When to escalate to vendor or Microsoft support
- Reproducible crashes or unhandled exceptions in the web part that can’t be resolved by configuration changes.
- Behavior inconsistent with documented functionality even after environment verification (permissions, compatibility).
- Throttling or performance issues tied to SharePoint Online service limits—contact Microsoft if platform-side throttling persists despite optimizations.
- If the web part was customized/extended, provide vendor or support with a reproduction page, console logs, ULS logs (if applicable), and exact SharePoint/version/browser details.
Include in your support ticket:
- Steps to reproduce
- Screenshots of the issue and console errors
- Relevant web part configuration screenshots
- A copy of any failing network requests (URL, response code, body)
- SharePoint version, web part version, browser/version, and user permission level
10. Checklist: Quick fixes to try first
- Test in another browser or private window.
- Re-save web part settings and/or reset to defaults.
- Ensure required libraries/resources load over HTTPS and aren’t blocked.
- Confirm user permissions to source lists and data.
- Index filter columns and minimize returned columns for performance.
- Inspect console and network errors; collect logs before changing configuration.
If you want, I can tailor this article for SharePoint Online vs on-premises, add step-by-step reproduce-and-fix examples for a specific error shown in your console, or produce a checklist you can paste into a ticket. Which would you prefer?
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