Expert Advice

[expert-advice]

External Guest Access to SharePoint Online Subfolders with Restricted Permissions

Can External Guests Access Restricted SharePoint Online Subfolders?

Yes. Sharing a parent folder with an external guest can sometimes allow access to subfolders, even when those subfolders have unique permissions.

Best practice: • Remove external sharing from the parent folder • Review active sharing links • Keep restricted folders on unique permissions • Share only the specific folders the guest needs • Use Specific people links • Verify access with Manage access and Check permissions

Tip: For frequent external sharing, consider using a separate document library for guest-facing content.

📖 Read the full guide:

External Guest Access to SharePoint Online Subfolders With Restricted PermissionsLearn why external guests may still see restricted SharePoi

[expert-advice]

Microsoft Teams PowerShell: Get-CsOnlineLisCivicAddress Returns “-1” for VoiceUsers and Phone Numbers

If you're seeing -1 for NumberOfVoiceUsers or NumberOfTelephoneNumbers when using Get-CsOnlineLisCivicAddress or Get-CsOnlineLisLocation, you're not alone.

I recently explored why this happens in Microsoft Teams PowerShell and shared a practical workaround that accurately identifies unused Emergency Addresses by correlating CivicAddressId with phone number assignments. The guide also covers the hidden 500-result limitation in Get-CsPhoneNumberAssignment and how to handle it using pagination.

A useful resource for Microsoft Teams administrators looking to clean up unused LIS locations and improve E911 management.

If you have ever tried auditing Emergency Addresses in Microsoft Teams PowerShell using Get-CsOnlineLisCivicAddress or Get-CsOnlineLisLocati

[expert-advice]

Microsoft Teams Error Code 399287: Unable to Verify Identity via SMS

Locked out of Microsoft Teams with Error Code 399287?

If you're seeing the message "Sorry, we're having trouble verifying your account. Please try again." during SMS verification, the issue is usually related to Microsoft Entra MFA—not your Teams app or computer.

In my latest guide, I cover:

What causes Error 399287 in MS Teams

Why SMS verification fails

How to recover access

When to contact Microsoft Support

Best practices to avoid future MFA lockouts

If you manage Microsoft 365 or support Teams users, this guide can help you resolve the issue faster.

Complete Fix Guide for Microsoft Teams Error Code 399287. If you’re seeing the message: “Sorry, we’re having trouble verifying your account.

[expert-advice]

Google Calendar and Microsoft Teams: Why You Can’t Add Co-Organizers (Complete Fix)

This issue looks like a bug, but in most cases it is actually caused by organizer ownership conflicts between Google Calendar and Microsoft Teams.

If you inherited the event or recreated the Teams link later, Teams may still recognize another account as the true organizer behind the meeting.

That’s why the co-organizer dropdown appears incomplete or restricted.

How to Fix - When you can’t add Co-Organizers in Google Calendar and Microsoft Teams. If you inherited a Google Calendar event and added a n

[expert-advice]

Exchange Hybrid Mailbox Migration: Step-by-Step Guide with Minimal Downtime

Planning an Exchange hybrid mailbox migration?

This step-by-step guide explains how to move mailboxes from on-prem Exchange to Microsoft 365 with minimal downtime, no mail flow disruption, and happy users.

Covers hybrid prerequisites, large mailboxes, Outlook behavior, and when to use tools like Stellar and SysTools.

Read the full guide:

Step-by-step Exchange hybrid mailbox migration guide covering prerequisites, remote move batches, large mailboxes, and third-party tools. Ex

[expert-advice]

How to Fix AADSTS90023 & AADSTS9001026 in Microsoft Teams

Struggling with AADSTS90023 or AADSTS9001026 errors in Microsoft Teams—especially for guest users on Android?

This isn’t a simple sign-in issue. It’s usually a cross-tenant token validation problem in Azure AD (Entra ID), and the Teams mobile app is where it breaks most often.

I’ve shared a step-by-step guide covering: ✔ Why Teams Web works but mobile fails ✔ How to fix token cache issues ✔ When Microsoft Authenticator helps ✔ When it’s time to escalate to Microsoft Support

If you manage B2B guest access, this one’s worth bookmarking.

Read the full guide here:

Learn how to fix AADSTS90023 and AADSTS9001026 errors in Microsoft Teams guest sign-ins on Mobile apps. Step-by-step Azure AD solutions. Mic

[expert-advice]

Delete Microsoft Teams Chats: Complete User & Admin Guide

Deleting Microsoft Teams chat history isn’t always permanent—and that surprises a lot of people.

This guide explains: • How users delete chats • Why admins must use eDiscovery • How retention policies automate cleanup • What other participants still see

If you use Microsoft Teams at work, this is worth knowing.

Learn how to delete Microsoft Teams chat history using eDiscovery, retention policies, or user settings. Covers 1:1, group, and meeting chat

[expert-advice]

Microsoft Teams Channel Restore Search Issue Explained | Fix Missing Channel Messages After Restore

Ever restored a private channel in Microsoft Teams and noticed old messages missing from search? You’re not alone — it’s actually expected behavior!

Here’s why: when you restore a Teams private channel, Microsoft runs a background re-indexing process that can take up to 72 hours before all messages become searchable again.

In our latest guide, we explain why this happens, how to check if your content is healthy, and what steps can help speed it up. Perfect for IT admins, Teams managers, and anyone responsible for collaboration governance.

Read the full guide:

How to Fix Missing Channel Messages After Restore - Restored a private channel in Microsoft Teams, but can’t find your older messages in sea

[expert-advice]

How to Set Up PSTN Calling in Microsoft Teams

Did you know you can turn Microsoft Teams into your full business phone system?

With PSTN calling, you can make and receive traditional phone calls right inside Teams — no extra hardware needed.

Our latest guide covers: Microsoft Teams PSTN calling setup

How to set up Teams Phone

Assigning numbers & Caller ID

Emergency calling & call queues

Read the full step-by-step guide:

Microsoft Teams PSTN calling setup - Enable PSTN calling in Microsoft Teams with this complete setup guide. Learn how to configure Teams Pho

[expert-advice]

Exchange Server SE and Active Directory Schema Duplication Bug: A Migration Story

Exchange Server SE + Active Directory Migration Gone Wrong (Migration Story)

Upgrading to Windows Server 2025 Domain Controllers and Exchange Server SE? Here’s a must-read case study of a real-world migration that uncovered a Microsoft schema replication bug — causing Event ID 1203, lsass.exe CPU spikes, and schema replication failures across mixed environments.

If you’re running Exchange hybrid, this bug could impact you too.

Read the full breakdown, root cause, and advanced workaround here:

When it comes to Active Directory migrations and Exchange Server upgrades, even the most carefully planned deployment can take an unexpected

[expert-advice]

Active Directory Replication Issues: Common Causes, Fixes & Troubleshooting Tips

Struggling with Active Directory replication issues?

From DNS errors to time sync failures — even small misconfigurations can break your entire network replication.

Learn how to diagnose, fix, and prevent AD replication errors like a pro. Keep your domain controllers healthy and your users connected — always.

Read the full troubleshooting guide here:

Learn how to diagnose and fix common Active Directory replication issues - including DNS errors, network failures, and time sync problems. A

[expert-advice]

Best Video Recovery Software for iPhone, Android, Windows & Mac

Lost your important videos? Don’t panic — you can get them back!

We tested and compared the Top 3 Video Recovery Software for iPhone, Android, Windows & Mac — including Stellar, EaseUS, and Wondershare Recoverit.

Find out which one truly works for deleted, formatted, or corrupted videos.

Read the full guide here:

Losing your precious videos - whether family memories, YouTube footage, or professional projects - can be heartbreaking. Luckily, modern bes

[expert-advice]

Best Photo Recovery Software for iPhone, Android, Windows & Mac

Lost your precious photos? Don’t panic — recovery is possible!

Check out our latest guide on the Best Photo Recovery Software for iPhone, Android, Windows, and Mac. From accidental deletions to corrupted SD cards, discover the tools that actually work.

Read the full comparison & pick the right one for you:

Lost photos on iPhone, Android, Windows, or Mac? Discover the best photo recovery software for iPhone, Android, Windows & Mac. Features, pri

[expert-advice]

How to Fix iPhone Keeps Restarting or Boot Loop iPhone 15, 16, 17 & iOS 17/18/26

iPhone Keeps Restarting or Stuck in Boot Loop?

If your iPhone 15, 16, or 17 keeps turning off and on, or gets stuck on the Apple logo — don’t panic! We’ve compiled a complete step-by-step guide to fix restart loops, software glitches, and iOS update issues.

From draining your battery to DFU mode and Apple Support solutions — we’ve covered everything to get your iPhone running smoothly again!

Read the full guide here:

Fix the iPhone that keeps restarting or is stuck on the Apple logo loop. Works with iPhone 15, 16, 17 on iOS 17, 18, and 26. Easy, proven tr

[expert-advice]

iPhone Is Disabled or Unavailable? Data Recovery, Fixes, and Backup Solutions

Locked out of your iPhone? Seeing “iPhone Unavailable” or “iPhone is Disabled”?

Here’s the truth data recovery is only possible if you have a backup. No backup = no recovery.

But don’t worry—there are safe ways to erase, reset, and restore your iPhone so you can get back to using it.

Read the full guide here:

Learn how to fix an iPhone showing “Unavailable” or “Disabled,” recover data from backups, and prevent future lockouts with iCloud or iTunes

[expert-advice]

AI Agents vs Agentic AI: The Next Big Shift in Artificial Intelligence

AI Agents vs. Agentic AI: What’s the Difference?

AI is evolving fast, but many people confuse AI Agents with Agentic AI. AI Agents = digital specialists that handle specific tasks (like chatbots, IT ticket bots). Agentic AI = the orchestrator that takes initiative, coordinates multiple agents, and drives outcomes like a strategic manager.

In short: AI Agents complete tasks. Agentic AI achieves goals.

Read the full breakdown here:

Artificial Intelligence (AI) has evolved from a buzzword to a game-changer in the business world. Today, it's seamlessly integrated into eve

[expert-advice]

Agentic AI Threats: How Autonomous AI Is More Dangerous Than Deepfakes

While deepfakes manipulate content, agentic AI can act on its own—moving money, leaking data, impersonating employees, and launching cyberattacks at scale.

We’re not just facing fake videos anymore. We’re facing autonomous AI systems that make decisions without human oversight.

Businesses need to rethink AI security now—before agentic AI becomes the biggest cybercrime engine we’ve ever seen.

Deepfakes are scary. But Agentic AI? That’s next-level dangerous.

When deepfakes first exploded into the headlines, they felt like the ultimate AI nightmare. Fake videos of presidents saying things they nev