Sync errors
Fixes for scheduled Notes that didn't reach Substack or didn't post, a missing Sync button, extension not detected, scheduling limits and Substack rate limits.
A scheduled Note posts only after it is on Substack. If it never got there, it doesn't go out. Find your symptom below. For how syncing works, see Sync.
My Note didn't post
Why: The Note was scheduled in WriteStack but never synced to Substack. This happens when you schedule from your phone, from an AI assistant through MCP, or when the extension wasn't available. Once its time passes, WriteStack no longer offers to sync it, and the time shows in red in your queue.
Fix:
- On a computer with the extension, open My Notes → Scheduled notes.
- Open the Note. Set When to Now and click Post Now, or pick a new time and add it to the queue again.
- To clean up several past Notes at once, click Sync now next to "Last synced on". In Review Substack sync, choose Archive or Move to Drafts for each Note with a past schedule.
To avoid this, sync right after scheduling without the extension (next section).
I see "Sync N scheduled notes to Substack"
Why: These Notes are scheduled in WriteStack but not yet on Substack.
Fix: Click the button and wait. While it runs you'll see "Syncing. Do not close WriteStack". Keep the tab open until it finishes with "All the notes are synced to Substack". To sync a single Note, click the warning icon next to it in the queue, or click Sync to Substack in the editor.
I don't see the Sync button
Why: The button only shows on large screens, and only when there are future Notes that aren't on Substack yet.
Fix:
- Open WriteStack on a computer, in a wide browser window.
- Go to My Notes → Scheduled notes.
- If there's still no button, every future Note is already on Substack.
"Chrome Extension Required"
Why: WriteStack couldn't detect the extension in this browser. It may not be installed, may be turned off, or the page loaded before it was ready.
Fix:
- Click Install the extension, or check that WriteStack is turned on at
chrome://extensions(about:addonsin Firefox). - Click (Refresh after installation) or reload the page.
- Make sure you're on a computer. The extension doesn't run on phones.
See Install the browser extension.
"Failed to schedule note" or "Failed to sync schedule to Substack"
Why: The extension couldn't create the schedule on Substack. Common causes: you're logged out of Substack, a different Substack account is logged in, or the extension is out of date.
Fix:
- Log in to Substack in the same browser, with the account that owns your publication.
- Update the extension and refresh WriteStack.
- Try again. If it keeps failing, contact support with the exact message.
"You've reached your scheduling limit"
Why: Your plan allows a set number of scheduled Notes at a time, and syncing would go over it. See Capacity.
Fix: In the dialog, click the button to sync what fits and move the rest to Ready. Nothing gets deleted. Schedule the rest once earlier Notes have posted, or upgrade your plan.
If you schedule a single Note over the limit, you'll see "You have reached the maximum number of scheduled notes".
Syncing pauses with "waiting for Substack"
Why: Substack allows up to 50 new schedules every 3 minutes. When you schedule or sync more than that, WriteStack pauses and shows a countdown.
Fix: Leave the tab open. It resumes on its own.
"Substack allows scheduling up to 3 months ahead"
Why: Substack accepts scheduled Notes up to 90 days ahead.
Fix: Pick a date within the next 90 days.
"You can't schedule a note in the past"
Fix: Pick a future time, or set When to Now and click Post Now.
"Failed to save N scheduled notes. They were rolled back on Substack."
Why: The Notes were scheduled on Substack, but WriteStack couldn't save them, so it removed them from Substack to keep both sides matching.
Fix: Run the sync again. If it repeats, contact support.
"Couldn't sync schedules with Substack. Click to try again."
Why: WriteStack couldn't read your scheduled Notes from Substack.
Fix: Click the message to retry. Check that the extension is on and you're logged in to Substack.
A Note shows "N changes from Substack"
Why: Someone changed, deleted or added a scheduled Note directly on Substack. See Schedule mismatch.
Still stuck
Contact support. Include the Note, the time it should have posted and the exact error.
Substack connection problems
Fixes for errors when connecting your Substack profile in onboarding, when Notes post from the wrong account, and when the extension can't reach your Substack.
Notes post at the wrong time
Why a Note posts at an unexpected time or lands in a different queue slot than you expected, and how to fix time zones, tag routing, unmatched notes and queue edits.