Before a post is saved, Postalu checks it against what each platform accepts. A check that fails shows its message in red and stops you moving on. In messages that begin with <Platform>, that is the network's name.
| Message | Fix |
|---|---|
| Media file is empty or corrupted. | Choose a different file. |
| File is larger than the 500MB size limit. | Export a smaller file. |
| Select at least 2 images for a slideshow. | Add another photo, or post a single photo. |
| Write the text of your post. / Write the poll question. | Fill the caption box for text, link and poll posts. |
| Enter a full link starting with http:// or https://. | Fix the link in a link post. |
| A poll needs 2 to 4 options. / Poll options can't be empty. / Poll options can be at most 25 characters. / Poll options must be different. / A poll can run from 5 minutes to 7 days. | Fix the poll. |
| <Platform> can't publish posts without a photo or video. | Add media or untick the platform. |
| <Platform> doesn't support polls through its API. Polls work on X. | Post the poll to X only. |
| Stories must be a single photo or video. | Use one file and no text-only post. |
| <Platform> doesn't support Stories. | Untick it or switch to a Feed post. |
| <Platform> only supports video broadcasts (Shorts/Videos). | YouTube needs a video. |
| <Platform> doesn't support multi-image slideshow posts. / <Platform> supports up to N images per slideshow. | Untick it or remove photos. |
| Caption is too long for <Platform> (max N characters). | Shorten it, or untick that platform. |
| Description is too long for <Platform> (max N characters). | Shorten the description. |
| YouTube titles can be at most 100 characters. | Shorten the title. |
| First comment is too long for <Platform> (max N characters). | Shorten it. TikTok's limit is 150. |
| TikTok: Choose who can view your TikTok post. | See TikTok settings. |
| Choose a valid date and time. / Pick a time at least 2 minutes from now. / Posts can be scheduled up to 30 days ahead. | See Scheduling rules. |
| You don't have permission to publish to: … | A platform on the post needs a permission you lack. |
| One of the selected accounts is no longer connected. | Reconnect the account or untick it. |
| Invalid post data. | Reload and try again; if it repeats, remove the last change you made. |
| A caption, comment, poll option or link is too long or contains characters that can't be used. | Remove unusual control characters; a caption can be up to 10,000 characters before platform limits. |
| Instagram photos must be between 4:5 and 1.91:1; this one is W×H. Crop it first. | Crop the photo. |
| Threads videos can be at most 5 minutes; this one is M:SS. / Instagram Story videos can be at most 60 seconds; this one is M:SS. | Trim the video or untick the platform. |
Read next
- Photo and video requirements, and why a file is blocked or warned about Accepted formats, the 500 MB limit, the length and shape checks, and every message you can see.
- Caption, description, tags and first comment What each text field does, which platforms use it, and the length limits.
- Scheduling rules and the messages you may see Every scheduling limit in one table, with the exact message for each.
