A scheduled post failed to publish: what to do

If a post on your Calendar failed to publish, here's how to fix it.

Quick checks

1. Open the failed post on the Calendar.
2. Read the message at the top of the post, under Failed to publish.

The message usually points straight at the cause. Mavic now explains platform problems in plain language, such as an expired connection, instead of a generic "Server Error". Common causes are below.

Common causes and fixes

The channel's connection expired

• Symptom: the message says the channel is no longer valid, its session expired, or it needs to be re-authenticated. You may also have a notification about it, and the channel shows a warning in Integrations.
• Fix: open Integrations, click the channel's … menu and choose Re-authenticate. Then publish the post again (see below).

LinkedIn posts failed between 15 and 19 October 2026

• Symptom: a LinkedIn post failed with only "Server Error".
• Cause: LinkedIn retired the version of its API that Mavic used. Publishing was restored on 19 October.
• Fix: nothing to change on your side; publish the post again.

Image format not supported

• Symptom: the message mentions image dimensions, file size or format.
• Fix: remake the image with the right aspect ratio, or upload a new one. Each platform has its own specs:
• • Instagram feed: 1:1 or 4:5, JPEG/PNG, max 30MB
  • Stories/Reels: 9:16, MP4 for video
  • LinkedIn: PDF for carousels; JPEG/PNG for single images
  • X: JPEG/PNG/GIF, max 5MB

Video too long or wrong format

• Symptom: a Reel, TikTok or Story video failed.
• Fix: check the video meets the platform's spec (MP4, vertical 9:16, within the platform's length limit). Re-export it and attach it again.

Caption too long for the platform

• Symptom: the message mentions character count.
• Fix: in the Post editor, turn on Customize per channel and shorten the caption for that platform. See Editing captions per platform.

Tag or mention couldn't be resolved

• Symptom: an @mention in the caption is invalid.
• Fix: check the username or URL is correct. For LinkedIn, only company or organization URLs are accepted. See Tagging companies and users.

Rate limited by the platform

• Symptom: the message mentions a rate limit or too many requests.
• Fix: wait 10–15 minutes and try again. If it keeps failing, space your scheduled posts further apart.

Platform-side outage

• Symptom: the message mentions a platform server error or service unavailable.
• Fix: check the platform's status page (for example Meta Status or X Status). If the platform is down, try again later.

Publishing a failed post again

A failed post can't be edited or retried directly. Instead:

1. On the Calendar, open the failed post's … menu and click Make a copy.
2. The copy opens in the Post editor with the same caption and media. Fix what caused the failure.
3. Schedule it, or publish it straight away.

You can also ask Mavic in chat to publish the post again. Mavic shows you a confirmation first and posts only after you approve. If the channel isn't connected any more, Mavic tells you to re-authenticate it in Integrations first.

Getting told about failures sooner

• Connect Slack and failures arrive in your Slack channel straight away. See Connecting Slack for notifications.
• Mavic also sends you a notification when a channel's connection is no longer valid.

What if the post partly succeeded?

If you scheduled a post to several channels and only some failed:

• The channels that succeeded are live; nothing to do.
• Each failed channel shows as failed on its own. Fix and publish each one again separately.

Related articles

• Multi-channel publishing
• Can't connect a social channel?
• Social channels invalidated
• Connecting Slack for notifications

Updated: November 2026

Updated on: 01/11/2026