SharePoint Common Issues: Troubleshooting Guide 2026

1. Permissions Inheritance Broken Across Sites

This is the single most common governance failure in SharePoint Online. Over time, site owners break inheritance at the library, folder, and item level to grant one-off access. After a few years, you end up with a permissions model that no one understands and no one can audit manually.

Symptoms: Users who should have access cannot see files. Users who should not have access can see everything. Copilot surfaces documents it should not. Audit reports show thousands of unique permission entries.

Fix: Use PnP PowerShell to enumerate all objects with unique permissions: Get-PnPListItem -List "Documents" | Where-Object { $_.HasUniqueRoleAssignments }. For each, decide whether to restore inheritance or document the exception. EPC Group's governance framework caps unique permissions at 5% of objects per site collection and requires documented justification for each exception.

2. Search Not Returning Results

SharePoint search issues fall into three categories: content not indexed, managed properties not mapped, and permission trimming hiding results from the user.

Content not indexed: Check if the library has search enabled (Library Settings > Advanced Settings > Allow items to appear in search). Check if the site is included in the search schema. Request a re-crawl from the SharePoint Admin Center.

Managed properties not mapped: If you are searching on custom columns, the crawled property must be mapped to a managed property in the search schema. Go to SharePoint Admin Center > Search > Manage Search Schema to verify mappings.

Permission trimming: Search results are filtered by the user's permissions. If a user cannot see a document in search, they likely do not have access to the library or site. This is often confused with a search indexing issue.

3. OneDrive Sync Conflicts

Sync conflicts spike when organizations have remote workers editing files offline or when file paths exceed 400 characters. The OneDrive sync client (OneDrive.exe) creates conflict copies with the user's name appended, but users rarely notice until their folder is cluttered with duplicates.

Fix: Enable Files On-Demand to reduce offline editing. Enforce co-authoring policies through Microsoft 365 admin settings. Use the OneDrive admin reports to identify users with high conflict rates and address their specific workflows.

4. SPFx Web Part Deployment Failures

SPFx (SharePoint Framework) deployment failures are the most common developer-facing issue. The usual culprits: wrong Node.js version, missing API permission approvals, tenant-scoped deployment not checked, or CDN configuration errors.

Fix: Verify Node.js version matches SPFx requirements (Node 18.x for SPFx 1.18+). After uploading the .sppkg to the App Catalog, check the deployment panel for API permission requests and approve them in the SharePoint Admin Center. Check browser F12 console for specific load errors. Use gulp serve locally first to catch build errors before packaging.

5. Migration Errors (On-Premises to SharePoint Online)

Migrations from SharePoint 2013/2016/2019 to SharePoint Online using SharePoint Migration Tool (SPMT) or third-party tools (ShareGate, AvePoint) commonly fail on: file path length exceeding 400 characters, unsupported characters in file names, custom workflows that do not have a Power Automate equivalent, InfoPath forms, and sandbox solutions.

Fix: Run the SharePoint Migration Assessment Tool (SMAT) before migrating to identify blockers. Remediate file paths and characters in the source environment first. Map custom workflows to Power Automate flows before migration — do not assume they will migrate automatically. EPC Group's SharePoint migration practice pre-remediates all blockers in the source environment before starting the migration, which reduces migration failure rates from 15-20% to under 2%.

6. Large List Throttling (5,000-Item Threshold)

The 5,000-item list view threshold is the most misunderstood limit in SharePoint. It does not mean lists are capped at 5,000 items. Lists can hold 30 million items. The threshold applies to a single view load — if your view tries to render or sort/filter more than 5,000 items without an indexed column, SharePoint blocks it.

Fix: Index the columns used in view filters and sorts (List Settings > Indexed Columns). Create views with filters that reduce the result set below 5,000. For programmatic access, use REST API with $top=100&$skiptoken pagination. Consider moving lists with 100K+ items to a Dataverse table or Azure SQL backend if complex querying is needed.

7. Custom Columns Missing After Migration

After migrating content between site collections or from on-premises, custom site columns and content types sometimes appear as missing or disconnected. This happens when columns were created at the list level rather than the site level, or when content type IDs change during migration.

Fix: Before migration, ensure all columns are defined at the site content type level, not the list level. After migration, use PnP PowerShell to compare source and destination content types. Re-associate content types if needed using Set-PnPContentType. For large migrations, EPC Group scripts content type validation as a post-migration check.

8. Workflow Failures (Power Automate and Legacy)

SharePoint 2010 and 2013 workflows are deprecated and will stop working in 2026. Power Automate flows that connect to SharePoint commonly fail on: throttling (429 errors), missing permissions (the flow connection user left the organization), trigger delays (up to 15 minutes for item-created triggers), and nested loop timeouts.

Fix: Migrate legacy workflows to Power Automate immediately — the deprecation deadline is real. For Power Automate throttling, implement retry policies and reduce batch sizes. Use service accounts for flow connections instead of individual user accounts. For trigger delays, switch to webhook-based triggers where possible.

9. External Sharing Blocked or Misconfigured

External sharing in SharePoint Online is controlled at four levels: tenant, site collection, individual site, and item. When users report that external sharing is not working, the issue is almost always a conflict between these levels — the tenant allows sharing but the specific site collection does not, or the site allows sharing but an admin policy overrides it.

Fix: Check the sharing hierarchy: SharePoint Admin Center > Policies > Sharing (tenant level), then individual site settings. Ensure the target site's sharing level is equal to or more restrictive than the tenant level — it cannot be more permissive. Verify Azure AD B2B settings if external users need to authenticate. Check conditional access policies that may block external guest access.

10. Teams and SharePoint Disconnect

Every Microsoft Teams team creates a SharePoint site for file storage. Problems arise when: site permissions drift from Teams membership (someone added directly to the SharePoint site but not the Teams team), file versioning settings differ from what Teams users expect, or the SharePoint site URL is changed after Teams creation.

Fix: Never manage SharePoint permissions directly on a Teams-connected site — manage membership through the Teams admin. Set versioning policies on the SharePoint library to match organizational retention requirements. If the site URL was changed, update it through the SharePoint Admin Center (Rename site) and allow 24 hours for propagation.

Issues 11-20: Quick Reference

Frequently Asked Questions