Mixpanel Import Failed or Events Dropped

How to fix it

Try these in order — the most common fix is first.

1. 1. Fix timestamps

   Copy steps
   1. Filter or correct future timestamps in the warehouse and re-sync
   2. Fix unparseable timestamp columns (whole sync fails otherwise)
   Did this fix it? Yes No

2. 2. Map a unique Insert ID

   Copy steps
   1. Map a unique string column as Insert ID in the sync
   2. A column named insert_id that is not mapped imports as a normal property
   Did this fix it? Yes No

3. 3. Find the import

   Copy steps
   1. Use the Mixpanel Import ID in the Sync History tab
   2. Filter reports on $warehouse_import_id and $warehouse_type
   Did this fix it? Yes No

Symptoms

Warehouse sync or Import API run finishes but events are missing, trimmed or duplicated.

Why it happens

• Timestamp more than 1 hour in the future (dropped)
• Event older than project retention
• Event over 1MB uncompressed JSON
• Strings over 255 bytes or list/object properties over 8KB are trimmed
• No Insert ID mapped, so identical rows merge

This guide also covers

• mixpanel import failed
• mixpanel import events error
• mixpanel warehouse sync missing events

Other Mixpanel errors

• Mixpanel Events Not Showing
• Mixpanel Not Tracking: Blocked by Ad Blocker
• Mixpanel Identify Not Merging Users
• Mixpanel Data Delay: Events Late in Reports
• Mixpanel Event Limit Exceeded and Overage Bill
• Mixpanel Session Replay Not Working
• Mixpanel Users Reset Across Subdomains
• Mixpanel /decide and /flags Requests Failing