Media requirements, what you can't do, and common LinkedIn errors

Media Requirements

Type	Format	Max Size	Notes
Single Image	JPEG, PNG, GIF	5 MB	1200x627 (1.91:1) recommended
Video	MP4 H.264/AAC	500 MB	3s-30min, 75 MB recommended
Carousel	JPEG, PNG	10 MB/card	2-10 cards, 1080x1080
Document	PDF, PPT, DOC	100 MB	rendered as a swipeable document
Text ad logo	JPEG, PNG	2 MB	100x100

Media URLs must be publicly accessible; LinkedIn (via Zernio) fetches and re-hosts them under the Company Page or ad account.

What You Can't Do

Run from-scratch ads without a Company Page the member can post DSC for (Administrator or Direct Sponsored Content Poster role required, or 403)
Get profile-prefilled Lead Gen Form fields (EMAIL, FIRST_NAME, ...) via the API — Campaign Manager UI only; API forms take text and multipleChoice questions
Receive lead webhooks: LinkedIn has no lead push, poll GET /v1/ads/leads (90-day retention)
Hard-delete a Lead Gen Form (archive only) or a conversion rule (soft-disable only)
Append to a contact-list audience: every upload is a full replace
Get daily time series on firmographic pivots (LinkedIn aggregates over the whole range, timeGranularity: ALL)
Budget below $10/day, or $100 lifetime on inactive campaigns
Use dynamic UTM params on Conversation, Message, or Lead Gen Form ads
Send conversion events older than 90 days
Sponsor a member post by URL alone: activity URNs are rejected, you need the -share- / -ugcPost- id from "Copy link to post"

LinkedIn's REST errors surface verbatim inside Zernio's platform_error envelope. The recurring ones:

Error	Where	Meaning + fix
`403` on create	From-scratch ads	The member lacks the DSC Poster / Administrator role on the Page, or the Page isn't associated with the ad account.
`403` `linkedin_reconnect_required`	Conversions API	The connection predates the `rw_conversions` scope. Reconnect the account.
`403` mentioning `partnerApiLeadGenFormResponse`	Lead responses	The connection lacks `r_marketing_leadgen_automation`. Reconnect the account.
`422` on reshare/sponsor	Thought-leader, boost	The post URN is an `activity` URN. Use the `share` / `ugcPost` id from "Copy link to post".
`SINMAIL_SENDER_NOT_APPROVED`	Conversation ads	The sender isn't approved for the ad account in Campaign Manager ("Manage message ad senders"), org senders included.
`422` "The objective type is not supported"	Supply forecast	`objectiveType` is required in practice despite being documented optional. Pass any valid objective.
`404` on dynamic-format creative	Follower, jobs, event ads	LinkedIn couldn't resolve the Page-side state (follow target, active job postings, real Event). Fix the Page, not the payload.
`Campaign quality score` rejections / stuck in review	Any	LinkedIn reviews every ad; a `DRAFT`/review state is normal for the first minutes-to-hours.

Two consistency notes that look like bugs but aren't:

Segment reads right after an upload can come back empty: LinkedIn's audience builds are eventually consistent. Re-read after a minute.
LinkedIn-Version deprecates monthly on LinkedIn's side. Zernio pins and rolls the version for you; you never send it, and version-related churn is absorbed server-side.

Type	Format	Max Size	Notes
Single Image	JPEG, PNG, GIF	5 MB	1200x627 (1.91:1) recommended
Video	MP4 H.264/AAC	500 MB	3s-30min, 75 MB recommended
Carousel	JPEG, PNG	10 MB/card	2-10 cards, 1080x1080
Document	PDF, PPT, DOC	100 MB	rendered as a swipeable document
Text ad logo	JPEG, PNG	2 MB	100x100

Media URLs must be publicly accessible; LinkedIn (via Zernio) fetches and re-hosts them under the Company Page or ad account.

Run from-scratch ads without a Company Page the member can post DSC for (Administrator or Direct Sponsored Content Poster role required, or 403)
Get profile-prefilled Lead Gen Form fields (EMAIL, FIRST_NAME, ...) via the API — Campaign Manager UI only; API forms take text and multipleChoice questions
Receive lead webhooks: LinkedIn has no lead push, poll GET /v1/ads/leads (90-day retention)
Hard-delete a Lead Gen Form (archive only) or a conversion rule (soft-disable only)
Append to a contact-list audience: every upload is a full replace
Get daily time series on firmographic pivots (LinkedIn aggregates over the whole range, timeGranularity: ALL)
Budget below $10/day, or $100 lifetime on inactive campaigns
Use dynamic UTM params on Conversation, Message, or Lead Gen Form ads
Send conversion events older than 90 days
Sponsor a member post by URL alone: activity URNs are rejected, you need the -share- / -ugcPost- id from "Copy link to post"

LinkedIn's REST errors surface verbatim inside Zernio's platform_error envelope. The recurring ones:

Error	Where	Meaning + fix
`403` on create	From-scratch ads	The member lacks the DSC Poster / Administrator role on the Page, or the Page isn't associated with the ad account.
`403` `linkedin_reconnect_required`	Conversions API	The connection predates the `rw_conversions` scope. Reconnect the account.
`403` mentioning `partnerApiLeadGenFormResponse`	Lead responses	The connection lacks `r_marketing_leadgen_automation`. Reconnect the account.
`422` on reshare/sponsor	Thought-leader, boost	The post URN is an `activity` URN. Use the `share` / `ugcPost` id from "Copy link to post".
`SINMAIL_SENDER_NOT_APPROVED`	Conversation ads	The sender isn't approved for the ad account in Campaign Manager ("Manage message ad senders"), org senders included.
`422` "The objective type is not supported"	Supply forecast	`objectiveType` is required in practice despite being documented optional. Pass any valid objective.
`404` on dynamic-format creative	Follower, jobs, event ads	LinkedIn couldn't resolve the Page-side state (follow target, active job postings, real Event). Fix the Page, not the payload.
`Campaign quality score` rejections / stuck in review	Any	LinkedIn reviews every ad; a `DRAFT`/review state is normal for the first minutes-to-hours.

Two consistency notes that look like bugs but aren't:

Segment reads right after an upload can come back empty: LinkedIn's audience builds are eventually consistent. Re-read after a minute.
LinkedIn-Version deprecates monthly on LinkedIn's side. Zernio pins and rolls the version for you; you never send it, and version-related churn is absorbed server-side.