Technical Support Guide: diagnosis and fix

Applies to: the 1Stream Client Chrome extension (sidebar) inside the Web Client or PWA app. Issue identified September 2026.

1. Symptom

The 1Stream sidebar opens normally inside the  Web Client (the Small / Medium / Large bar is visible at the top), but the panel below it is empty grey with a small "broken page" icon in the middle. The left side of the screen keeps working. Click-to-call and the identity banner may also work — only the embedded 1Stream Client is missing.

Figure 1 — The symptom: sidebar chrome present, portal area replaced by Chrome's broken-page icon.

Key facts about this issue:

It affects only SOME users of the same PBX, even with the same extension version. Others are fine.

It is not caused by cookies, the user's 1Stream account, the extension version, other extensions, or the network.

Reinstalling the extension, clearing 1Stream cookies, or signing out/in of 1Stream does NOT fix it.

It typically appears in the days after an extension version change and/or an account update.

2. The fix (per user, about 1 minute)

Method 1 — DevTools (preferred, most precise)

On the Web Client tab press F12 → Application tab.

Left panel → Service workers. You will see the worker for the PBX (Source: 3cx-worker.js).

Click "Unregister" on the right of that entry.

Close DevTools and reload the page (F5). Sign in again if prompted.

The 1Stream portal now loads in the sidebar.

Method 2 — Chrome settings (no DevTools)

Chrome menu → Settings → Privacy and security → Third-party cookies → "See all site data and permissions" (or Site settings → View permissions and data stored across sites).

Search for the PBX address and click the delete (trash) icon for the PBX site.

Reload the  Web Client and sign in again.

Note: Method 2 also clears the  login and site settings for that account, so the user will need to sign in to again. It does not touch 1stream or any other site.

Quick proof before fixing (optional)

In Application → Service workers, tick "Bypass for network" and reload. If the sidebar immediately shows the portal, the diagnosis is confirmed. Untick it afterwards and use Unregister — "Bypass" is a DevTools-only setting and is not a permanent fix.

3. What does NOT help (do not spend time on these)

Reinstalling or updating the 1stream extension.

Clearing cookies for portal.1stream.com or signing out of 1stream — the portal is already answering 200 OK.

Disabling other extensions — confirmed irrelevant.

Changing third-party cookie settings.

A new Chrome profile works, but only because it has no stored copy; it is not a fix.

4. Telling this apart from the "login form in the sidebar" case

If the sidebar shows the MTP / 1Stream login form instead of the broken-page icon, that is a DIFFERENT and normal situation: the user simply has no active 1Stream portal session in the browser (for example after closing Chrome). Signing in on that form, or opening the 1Stream portal in a normal tab and then reloading the browser session (CTRL + R), resolves it. No service-worker action is needed.