The Sidepanel does not load in the Outlook app

This article covers the Sidepanel failing to load when you use it as an Outlook add-in. If you use the browser extension instead, see The browser extension does not open or detect the page.

Which Outlook are you using?

Most blocked cases in the Outlook app 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.

The Sidepanel works out of the box on:

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

Most of the edge cases below are specific to 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.

One exception: a shared mailbox hidden from your organization's address list blocks the panel on every Outlook client, not just classic Outlook on Windows, because it prevents the panel from getting any mailbox context at all. That case is covered in The Sidepanel does not load for a shared mailbox.

If you see the "Outlook isn't connecting" screen

One specific failure has its own screen. When the panel opens but Outlook never answers it, the panel waits 20 seconds and then replaces the spinner with a screen titled Outlook isn't connecting, explaining that the add-in could not connect to Outlook.

That screen has a Reload add-in button, which is worth trying first, and below it a box labeled Diagnostics showing a short report. In the top right of that box is a small Copy diagnostics link.

If you have this screen, copy that report into your message to support@tekst.com. It tells us exactly where the panel got stuck and usually lets us pinpoint the cause in one step.

You will not see this screen for every problem. It is specific to Outlook not answering the panel, so if the panel fails in some other way, there is nothing to copy and the checks below are where to go.

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 https://api.tekst.ai and https://api.tekst.com load and are not blocked by a firewall, proxy, or content filter. The panel uses one of the two depending on how it was served, so ask your IT team to allow both, then reopen the panel. If the panel works on one network and not another, The Sidepanel does not load on your network covers that pattern in full.

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, contact support@tekst.com. Personal-mailbox failures are usually something we need to look into directly. If you got the Outlook isn't connecting screen, include its diagnostics report. If you did not, tell us what the panel shows instead and we will take it from there.

It is a shared mailbox

Most failures on Outlook desktop classic happen with shared mailboxes, and the fixes need a Microsoft 365 administrator. See The Sidepanel does not load for a shared mailbox, which is written to be handed straight to whoever manages your tenant.

The panel opens but stays blank

Symptom: The Tekst panel opens and then renders nothing at all, staying empty rather than showing an error.

This is uncommon now, so work through the checks above first. If the Tekst button is missing from the Outlook ribbon entirely, that is a different problem: see When IT policy blocks the Sidepanel.

Cause: Outlook does not draw the panel itself. It passes that job to a display component that comes with Windows. On older machines, or where that component is missing, Outlook falls back to a much older one that cannot draw the panel at all, so you get an empty space instead.

Fix: update Windows and Microsoft 365 (Outlook), then close Outlook completely and reopen it. In almost every case that is the whole fix.

You do not need to install that display component yourself. It is called the Microsoft Edge WebView2 runtime, and it reaches devices on its own through three separate routes, which is why it is nearly always there already:

• It is part of Windows 11.
• On Windows 10 it was rolled out automatically, to personal devices from mid-2022 and to managed and domain-joined devices from early 2023.
• Microsoft 365 Apps installs it as well, on any Windows device running a reasonably recent version of Office.

It also keeps itself up to date from then on, so there is nothing to maintain by hand.

If it really is missing

A missing runtime is almost always a setting your IT team controls rather than something to install yourself, because both automatic installations can be turned off centrally. Ask them to check:

• The WebView2 installation policy for Windows, which can be used to opt a device out of the rollout.
• Enable automatic installation of WebView2 Runtime in the Microsoft 365 Apps admin center, under Customization > Device Configuration > Modern Apps Settings.

If either is switched off, they can turn it back on or deploy the runtime directly. If you administer your own machine, Microsoft publishes the runtime as a free download under the name Microsoft Edge WebView2.

One thing worth knowing before anyone suggests it: installing or updating the Microsoft Edge browser does not bring the runtime with it. They are separate components, and the panel does not need the browser at all.

If the panel area is still empty after updating, contact support@tekst.com. There is no error screen to copy in this case, because nothing renders at all, so tell us your Windows and Outlook versions instead.

Still stuck?

Contact support@tekst.com and let us know which Outlook version you are using, whether it is a personal or shared mailbox, and what the panel shows. If you got the Outlook isn't connecting screen, add its diagnostics report. We are happy to join a short call to confirm the cause and walk through the change needed.