You choose Preview in a familiar document service and nothing seems to happen. Clicking repeatedly may create several pending operations without explaining the problem. Pause and check whether a new tab opened, a file reached Downloads, or the browser reported a blocked window.
Look for the blocked-window indicator
This guide concerns Chrome on a computer. When Chrome blocks a pop-up, its address bar can show an indicator. Open that control and inspect the listed link. Chrome lets you open the particular blocked window from there; you do not necessarily need to create a permanent exception.
For a fictional example, suppose you deliberately requested a preview of your own document. Match the window to that action and to the service you are using. A separate, unexpected offer that appears at the same moment is not part of the task merely because it is nearby. If the destination is unfamiliar, return to the service's own instructions before allowing it.
No blocked-window indicator means the cause is still uncertain. Check the page for an error or an unfinished export. Changing several browser settings at once makes it harder to know which change mattered.
Keep a lasting exception narrow
If you use the same trusted workflow regularly and it genuinely needs pop-ups, Chrome offers an option to always allow them for that site. Check the site shown in the permission before saving it. Keep the general default rather than enabling pop-ups everywhere for one preview.
Revisit the exception when you no longer need it and remove it or block that site's pop-ups again. Website notifications use a separate permission; approving notifications is not the same repair. On a managed work or school browser, the administrator may control these settings.
Finally, repeat the intended action once and check the resulting document. A window opening proves only that it opened, not that the export contains the right pages or the latest version.