The "Error while sending attachments" error means your LinkedIn or Sales Navigator Phantom couldn't attach a file to a message, usually because the file exceeds the platform's size limit (100MB for LinkedIn, 50MB for Sales Navigator), uses an unsupported format, or is being sent to a 2nd or 3rd degree connection who doesn't accept attachments. To fix it: verify your file meets LinkedIn or Sales Navigator's requirements, and limit your recipients to 1st degree connections, or remove the attachment entirely and send the message text only.
Heads up: this error can appear alongside a successful run status. Your Phantom may have processed members and sent messages correctly but failed on the attachment. Always check your logs for the full picture.
Why you're seeing this
Your automation may show one of these messages:
- "Error while sending attachments"
- "An error occurred while trying to send attachments"
- "An error occurred while trying to attach [file name]"
This error appears when your Phantom couldn't attach a file to a LinkedIn or Sales Navigator message.
How to fix it
Check your file
LinkedIn and Sales Navigator each have their own supported file types and size limits. If your attachment doesn't meet these requirements, the Phantom will fail to send it.
- For LinkedIn: see LinkedIn's official guide on supported media file types. The maximum file size is 100MB.
- For Sales Navigator: see LinkedIn's official guide on adding attachments in Sales Navigator. The maximum file size is 50MB per attachment.
If your file exceeds the size limit or uses an unsupported format, convert or compress it before relaunching. If compression isn't practical, host the file externally (Google Drive, Dropbox, etc.) and include the link in your message text instead of using an attachment.
Check your connection degree
Depending on the Phantom you're using, LinkedIn may not allow attachments to recipients you aren't directly connected with. If your input includes 2nd or 3rd degree connections, the attachment may fail even if the message itself is sent successfully.
How to test: Go to LinkedIn and try sending the same file directly to one of the recipients. If LinkedIn doesn't allow it from the UI, PhantomBuster can't bypass this restriction.
If this is the cause:
- Remove the attachment from your Phantom setup and send messages without it.
- Or limit your input to 1st degree connections only.
Frequently asked questions
Why did my Phantom show a successful run but still log an attachment error?
Because the message itself was sent successfully, only the attachment failed. The Phantom processes members and sends messages independently of attachments, so partial failures can look like full successes at the summary level. Always check your logs for the full picture.
What file types does LinkedIn accept as attachments?
See LinkedIn's official guide on supported media file types. The maximum file size is 100MB.
What file types does Sales Navigator accept?
See LinkedIn's official guide on adding attachments in Sales Navigator. The maximum file size is 50MB per attachment.
Can I send attachments to 2nd and 3rd degree connections?
Not reliably. LinkedIn restricts attachments to 1st degree connections in most cases. If LinkedIn doesn't let you send the file directly from the UI, PhantomBuster can't bypass that restriction.
How do I know if my attachment failed because of the file or the recipient?
Test by sending the same file manually from LinkedIn to one of the Phantom's recipients. If LinkedIn blocks it in the UI, the issue is connection-degree-related. If LinkedIn accepts it, the issue is file-related (size, format, or corruption).
Can I split a large file into smaller ones to work around the size limit?
That's one option. Alternatively, host the file externally (Google Drive, Dropbox) and include the link in your message text instead of using an attachment.
If the error keeps showing up
If you've checked the connection degree and file requirements and still see the error, get in touch with our Customer Care Team.
If possible, include:
- The name of the Phantom where you saw the error.
- The file name and type you were trying to attach.
- A screenshot of your logs showing the error.