The Update CRM button in the detail view header changes appearance depending on the status of that conversation. Reading this indicator lets you know at a glance whether you can open the Update CRM dialog or whether there's a warning to review.
Button states
Enabled. The button shows "Update CRM" with no additional indicator. Clicking it opens the dialog to send the information to the CRM.
With a warning dot. The button shows a warning dot. Hover over it to see the details in the tooltip.
Disabled. The button appears disabled and the dialog can't be opened from that conversation.
Last sync information
The button doesn't show an "up to date" status or last sync information (date, person who synced, linked contact or deal, or number of tasks).