The most common cause for this to happen is that your article does't have a version in the language that you currently have selected as default. Every time our integration is launched it will screen your Zendesk instance, looking for and listing articles in your current default language. Make sure your language settings are adequately configured.
Also, please bear in mind that Unbabel will read any updates when the tool is launched, so be sure to only log in to https://kb.unbabel.com after you finish and save all intended changes in Zendesk.
If the previously described situations are not the ones causing the issue, there is a possibility your Zendesk token has become invalid. Refresh it and try launching the integration tool again.
Should you still find any difficulties, please reach out to us at firstname.lastname@example.org with a detailed description of the problem and the steps you've been through. Please be sure to identify the article's title and the URL for the article in your Help Center. We will be glad to help.