69 common problems we fix · Updated regularly
The Windows, Exchange, Microsoft 365, smart card and printer problems people search for most. Find yours below, then hand it to a certified tech who fixes it remotely.
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The Microsoft Exchange Transport service fails to start, the Queue Viewer won't open, and no mail flows. You see Service Control Manager timeout errors (7000/7009) but almost nothing in the Exchange or application logs.
After a Microsoft security update, /ecp and /owa throw a 500 error or hang. The update may have failed partway through and left the server half-patched.
Messages to a specific external tenant bounce with 550 5.7.51 TenantInboundAttribution. SPF/DKIM may also show as failing on arrival.
Outlook and webmail stop connecting after the SSL/TLS certificate bound to Exchange expires.
A specific admin account gets access denied at /ecp even though remote PowerShell is enabled for them.
ECP or OWA takes a very long time to load (sometimes a couple of minutes), but the server's CPU, memory and disk are all healthy.
Mail for a newly added domain isn't recognized or routed because the environment doesn't yet list it as an accepted domain.
You need to promote a different address to the primary reply address, but it keeps reverting, or the object is synced from on-prem and the cloud admin center rejects the change.
Mail suddenly stops flowing in and out, and scanners can't send. The Exchange server's system drive is full or nearly full, often from logging that was left turned up or from a large mailbox move. Exchange protects itself by refusing new mail until space is freed.
A passive copy of a mailbox database in a Database Availability Group is stuck in FailedAndSuspended, with thousands of transaction logs waiting to copy. Redundancy for that database is effectively gone until it's reseeded.
After moving to new Exchange servers and shutting down the old ones, the offline address book stops updating, cloud mailbox moves fail, and eDiscovery or calendar sharing breaks. Some of Exchange's hidden system mailboxes were left on the old servers.
Some outbound messages go out fine while others sit in the queue for hours or never arrive. It started after older Exchange servers were powered off, and there's no clear error for users.
Users can't send or receive emails with larger attachments, like big scanned PDFs, and get a bounce saying the message is too large. Limits are often set differently in several places, so raising one doesn't fix it.
Internal mail works, but mail to certain outside organizations fails with 454 4.7.0. It often starts right after a certificate change on the mail server.
The Exchange Queue Viewer throws an error or won't connect, so you can't see whether mail is stuck. It usually means the transport service itself isn't running.
After the mail server's certificate was replaced, some users get certificate warnings, repeated prompts, or Outlook won't connect at all, while others are fine.
Installing the Exchange Online management module fails with a PackageManagement or module conflict error, so you can't connect to Exchange Online from PowerShell.
Connect-ExchangeOnline fails or signs into the wrong place when the tenant is in a government cloud like GCC High, even with the right account.
You try to change a user's email address or attributes in the Microsoft 365 admin center and it refuses because the account is synced from your on-premises Active Directory.
Files, folders and desktop shortcuts show a red X overlay instead of the green check, and syncing appears stuck.
Signing in with a CAC/smart card fails with an 'untrusted certification authority' message.
Digitally signing a PDF with a CAC in Adobe Acrobat/Reader fails with a smart card reset error, even though the card and reader test fine.
PKINIT/smart-card logon fails and the domain controller logs Kerberos event 4768 with result code 0x42 (KDC_ERR_CERTIFICATE_MISMATCH).
Installing RSAT from a local Features-on-Demand source fails with 0x800F0912 (source not found) or 0x800F0818 (identity mismatch), especially on an offline/air-gapped machine.
Policies don't apply on a domain-joined workstation; gpupdate reports errors (1058, 1030, 1096, 1129) or nothing changes.
Windows Update scans fail (for example 0x8024401F / HTTP 500), often pointing at a WSUS server that no longer exists, and updates won't install.
A deployed application prompts for its MSI source files or opens and immediately closes for some users.
Microsoft's 2011 Secure Boot certificates expire between June and October 2026. After they expire, affected machines still run but stop getting boot-level security updates.
The standard new-Teams installer (teamsbootstrapper.exe) silently fails on Windows Server 2019 terminal/RDS hosts.
A server is low on disk and old, unused user profiles are taking up space, but the usual 'last used' date looks wrong on every profile.
A Windows PC repeatedly shows 'Can't connect to this network' even after rebooting and reinstalling the adapter driver.
You added space to the disk, but Extend Volume is greyed out for C: because a small recovery partition sits between C: and the new free space.
You try to give a VM more disk space in the hypervisor, but the size field is locked or the change fails because the VM still has a snapshot.
Some PCs haven't received security updates in a long time. They're still on Windows 11 21H2, which stopped receiving updates in October 2024.
Remote PowerShell and Invoke-Command time out against workstations even though the machines are on and on the network.
A machine doesn't answer ping, but you can still Remote Desktop into it or it shows as active. Scripts that check 'is it online' with ping report it as down.
You copy and paste a task sequence in MDT Deployment Workbench to make a variant, but editing the copy changes the original too.
Photos and images in File Explorer show plain icons instead of previews, either in every folder or only in one.
An application deployment from Configuration Manager fails right away with 0x87D01106, before the installer even runs.
Deploying a big installer, like a 1 GB app, to a group of machines crawls, with each machine waiting its turn. Installing it locally on one machine is fast.
A command that pops a message up for logged-on users works in a normal prompt, but fails with 'msg is not recognized' when your deployment tool runs it.
You set folder permissions on workstations through Group Policy, but the folders still have the old permissions or the change keeps reverting.
A WSUS cleanup or deep-clean runs for days with no progress, and the WsusPool application pool keeps recycling mid-operation.
You need to bring a server current but can't or don't want to rely on WSUS, SCCM, or a third-party patch tool.
You ran a WSUS cleanup — sometimes for days — and afterwards the database and content folder are the same size as before.
A copier/MFP that sends scan-to-email through an Exchange relay suddenly can't send after an Exchange update.
Everyone can scan to email except one person, whose scans fail with DNS errors in the message-tracking log.
Tapping a CAC at the printer returns a message that there's no account for the user, even though the account is fine.
One-page scans arrive by email, but multi-page scans from the same copier never show up, with no error on the copier.
A user's account locks over and over, even right after it's unlocked and they haven't typed a wrong password. Something else is still trying an old password.
Signing into Microsoft 365 or SharePoint with a CAC or smart card fails with AADSTS500192. Often the card has more than one certificate and the wrong one is being picked.
Sign-in to a Microsoft 365 app or migration tool is blocked with error 53003. The account is fine, but the device or location doesn't meet the organization's access rules.
You add someone to a security group, but they still get access denied to the share, database or app. Nothing seems wrong with the group.
An account that should have access gets told it isn't authorized for remote login when connecting with Remote Desktop, even after being added to the right group.
Two people need to use the same Windows 10/11 workstation remotely, but when the second one connects the first is disconnected.
You need a support account to have admin rights on every workstation without touching each machine by hand.
A PowerShell script that shows a pop-up or loads .NET code fails with an error about Constrained Language Mode. Common on hardened and STIG'd machines.
A script won't run, either because script execution is disabled or because PowerShell warns that it was downloaded from the internet.
A script that looks fine throws parser errors, and the error shows odd characters like â€" where dashes or quotes were. It happened after copying the script from a web page or document.
A batch script fails with 'was unexpected at this time' as soon as it works with a path under Program Files (x86).
A script refuses to run because a required module is missing, and installing it fails because it needs PowerShell 7 while you're on Windows PowerShell 5.1.
An internal admin script you wrote gets blocked or quarantined by antivirus as if it were malware, often the moment it touches the clipboard or runs background jobs.
Google's Find Hub (formerly Find My Device) shows 'Couldn't load devices' instead of your phone, tablet or earbuds.
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