Troubleshoot the Tekst side panel in Outlook

If the Tekst side panel does not load in Outlook, this guide helps you find the cause and the change needed to get it working. Most blocked cases come down to a small number of setups that classic Outlook on Windows does not fully support, and each one has a fix that also leaves your configuration in a better, more secure state.

For how to install the side panel in the first place, see How to set up the Tekst Outlook App.

Start here: which Outlook are you using?

The side panel works out of the box on:

• Outlook on the web
• Outlook for Mac
• The new Outlook for Windows

The edge cases in this guide only occur in Outlook desktop classic on Windows. If you have a choice, the fastest fix is to open the same mailbox in the new Outlook for Windows or in Outlook on the web, where the panel loads without any extra configuration.

If you have to stay on Outlook desktop classic on Windows, use the sections below based on what you see.

When the panel cannot load, it shows an error page

If the panel cannot start, it no longer spins forever. After a short timeout it shows an error page with a Copy diagnostics button.

Whenever you contact us about a panel that will not load, click Copy diagnostics and paste the result into your message to support@tekst.com. That report tells us exactly where the panel got stuck and usually lets us pinpoint the cause in one step.

The panel does not appear at all

Symptom: The Tekst panel stays blank and never renders any content.

Cause: The panel needs a modern rendering engine (WebGL 2) to draw its interface. Outlook desktop classic hosts add-ins inside the Microsoft Edge WebView2 runtime, which supports WebGL 2. On older or misconfigured machines, Outlook can fall back to the legacy Internet Explorer engine, which cannot render the panel.

Fix:

• Make sure Windows and Microsoft 365 (Outlook) are fully up to date.
• Install or update the Microsoft Edge WebView2 runtime.
• Restart Outlook after updating.

If the panel still does not appear after updating, click Copy diagnostics on the error page and send it to support@tekst.com.

The panel shows an error or does not finish loading

Work through these checks in order.

Open an email first. The panel only activates while you are reading a specific message. If you open it from the folder or inbox view with no email selected, it cannot get the mailbox context and times out. Open an email so it shows in the reading pane or its own window, then open the Tekst panel.

Confirm Tekst is reachable. In a browser on the same computer, check that api.tekst.com loads and is not blocked by a firewall, proxy, or content filter. If it is blocked, ask your IT team to allow it, then reopen the panel.

If Tekst is reachable and an email is open, the next step depends on whether you are working in a shared mailbox.

It is a personal mailbox

If the mailbox is your own (not a shared mailbox) and the panel still fails, click Copy diagnostics on the error page and send it to support@tekst.com. Personal-mailbox failures are usually something we need to look into directly, and the diagnostics report is what lets us do that quickly.

It is a shared mailbox

Most failures on Outlook desktop classic happen with shared mailboxes. Run the three checks below. The third one, automapping, is the cause we see most often.

1. The mailbox is hidden from the address list

If the shared mailbox is hidden from the Global Address List (GAL), the panel cannot resolve it and fails to load.

Fix (Microsoft 365 administrator):

• Open the Exchange admin center at admin.exchange.microsoft.com.
• Go to Recipients > Mailboxes and select the shared mailbox.
• Turn off Hide from my organization's address lists (also shown as "Hide from address lists") and save.
• Alternatively, run this in Exchange Online PowerShell:

Set-Mailbox -Identity "sharedmailbox@yourcompany.com" -HiddenFromAddressListsEnabled $false

• Allow a short time for the change to propagate, then restart Outlook and reopen the panel.

2. The mailbox was added by signing in with its own password

A shared mailbox should be reached through delegated access, not by adding it as a separate account and signing in with a username and password for the mailbox itself. Direct password sign-in is not a supported or secure setup, and the panel does not work reliably with it.

Fix:

• In Outlook, remove the directly added account: File > Account Settings > Account Settings, select the shared mailbox account, and click Remove.
• Have a Microsoft 365 administrator grant the user access instead (see the automapping steps below), so the mailbox is added through delegation rather than a password.
• As a best practice, the administrator should keep sign-in blocked for the shared mailbox account. Shared mailboxes do not need their own password, and blocking sign-in is more secure and keeps every action tied to the individual user who performed it.

3. The mailbox was not added through automapping

This is the most common cause. When an administrator grants a user Full Access to a shared mailbox, Outlook normally adds it automatically through automapping. Mailboxes added this way work with the panel. As a rule of thumb, if the user could open the mailbox through their normal permissions, the panel will work.

Problems appear when the mailbox was added by hand as an extra account (automapping off) instead of appearing automatically. Some teams do this deliberately to keep the local Outlook cache (OST file) from growing, but the panel does not load reliably in that setup.

Fix:

• Ask a Microsoft 365 administrator to grant the user Full Access with automapping enabled. In Exchange Online PowerShell:

Add-MailboxPermission -Identity "sharedmailbox@yourcompany.com" -User "user@yourcompany.com" -AccessRights FullAccess -AutoMapping $true

• If Full Access was previously granted with automapping turned off, remove it and add it again with automapping enabled:

Remove-MailboxPermission -Identity "sharedmailbox@yourcompany.com" -User "user@yourcompany.com" -AccessRights FullAccess
Add-MailboxPermission -Identity "sharedmailbox@yourcompany.com" -User "user@yourcompany.com" -AccessRights FullAccess -AutoMapping $true

• In Outlook, remove any copy of the mailbox that was added manually, then restart Outlook. The mailbox should reappear automatically, and the panel should load.
• If you turned automapping off to control the size of the OST cache, see Slow shared mailboxes - cause and solution for other ways to keep the cache under control while keeping automapping on.

Still stuck?

If you have worked through the checks above and the panel still does not load, click Copy diagnostics on the error page and send it to support@tekst.com. Let us know which Outlook version you are using and whether it is a personal or shared mailbox. We are happy to join a short call to confirm the cause and walk through the change needed.