Issue with CSV Upload to Mixpanel: Missing Poly_alloted_2 Values

Mounesh T. · 2025-06-03T09:49:44.278Z

I uploaded a CSV to Mixpanel with two columns: `distinct_id` and `Poly_alloted_2`. Out of ~14,000 users, only around *6,000* profiles show the `Poly_alloted_2` value. The remaining *~8,000* show it as `undefined` ,even though the CSV has valid values for all rows, and all `distinct_id`s exist in the user profiles. Both fields were mapped correctly during import. why are some distinct_id's are not getting mapped.

Issue with CSV Upload to Mixpanel: Missing Poly_alloted_2 Values | Mixpanel Community

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kapa.ai
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Hi Mounesh T., Please stand by as I search the Mixpanel knowledge base for an AI-powered answer. I normally take about 15 seconds or so. In case AI cannot answer your question, feel free to reach out to Mixpanel support at mixpanel.com/get-support. If you have follow-up questions for this thread, please tag me again with your question: @kapa.ai <follow-up question> 👋
Feel free to ask a follow-up question once I've answered by mentioning me with @kapa.ai
kapa.ai
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Based on the knowledge sources, here are the most likely reasons why some of your user profiles show the Poly_alloted_2 property as undefined after your CSV import, even though the CSV had valid values and the distinct_ids exist: 1. Incorrect Identifier Mapping During Import If the wrong column was set as the $distinct_id during import, Mixpanel may have created new, empty profiles or failed to update the intended profiles. Always ensure the correct column is mapped as $distinct_id. You can check for this by reviewing the distinct_id values on the affected profiles. This is a common cause of "empty" or incomplete profiles after import. The documentation specifically notes:
This may occur if you set the incorrect column from your CSV as the $distinct_id during your import. You can see which column was erroneously set as the $distinct_id by checking the distinct_id value set on these empty profiles. As a best practice, always check the sample values shown in the import module for each selected profile property. [User Profiles FAQ]2. Unselected or Unmapped Columns During Import During the CSV import process, you must explicitly select which columns to import and map them to the correct Mixpanel profile properties. If you did not select the Poly_alloted_2 column or did not map it correctly for all rows, those values would not be imported. You must also choose the associated Mixpanel profile property that each CSV column will be associated with. [Importing Profiles via the UI]3. Profile Overwrite and Duplicates If you uploaded a profile with the same email or name as another existing profile but a different $distinct_id, you would create duplicates, not update the existing profile. Only the profile with the exact $distinct_id will be updated. If you import profiles using $distinct_id values that already exist, those profiles will be updated... if you upload a profile that has the same email address or the same name as another existing profile, but a different $distinct_id, you will be uploading duplicates—they will not be combined. [Importing Profiles via the UI]4. CSV Formatting Issues The documentation does not mention this explicitly, but if there are hidden formatting issues (e.g., extra spaces, invisible characters, or mismatched casing in distinct_id values), Mixpanel may not match the rows to existing profiles, resulting in missing property updates.What you can do:
- Double-check that the $distinct_id column in your CSV exactly matches the distinct_id values in Mixpanel (no extra spaces, correct casing). - Review the import process to ensure both columns were selected and mapped correctly. - Check a few of the affected profiles to see what distinct_id was set and if any new/empty profiles were created. - If the issue persists, try re-importing a small sample of the problematic rows and observe the result.If all mappings and values are correct and the issue remains, the knowledge sources do not provide further troubleshooting steps, and you may need to contact Mixpanel support for deeper investigation.References: - User Profiles FAQ - Importing Profiles via the UI
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kapa.ai
APP
·
·
Hi Mounesh T., Please stand by as I search the Mixpanel knowledge base for an AI-powered answer. I normally take about 15 seconds or so. In case AI cannot answer your question, feel free to reach out to Mixpanel support at mixpanel.com/get-support. If you have follow-up questions for this thread, please tag me again with your question: @kapa.ai <follow-up question> 👋
Feel free to ask a follow-up question once I've answered by mentioning me with @kapa.ai
kapa.ai
APP
·
·
Based on the knowledge sources, here are the most likely reasons why some of your user profiles show the Poly_alloted_2 property as undefined after your CSV import, even though the CSV had valid values and the distinct_ids exist: 1. Incorrect Identifier Mapping During Import If the wrong column was set as the $distinct_id during import, Mixpanel may have created new, empty profiles or failed to update the intended profiles. Always ensure the correct column is mapped as $distinct_id. You can check for this by reviewing the distinct_id values on the affected profiles. This is a common cause of "empty" or incomplete profiles after import. The documentation specifically notes:
This may occur if you set the incorrect column from your CSV as the $distinct_id during your import. You can see which column was erroneously set as the $distinct_id by checking the distinct_id value set on these empty profiles. As a best practice, always check the sample values shown in the import module for each selected profile property. [User Profiles FAQ]2. Unselected or Unmapped Columns During Import During the CSV import process, you must explicitly select which columns to import and map them to the correct Mixpanel profile properties. If you did not select the Poly_alloted_2 column or did not map it correctly for all rows, those values would not be imported. You must also choose the associated Mixpanel profile property that each CSV column will be associated with. [Importing Profiles via the UI]3. Profile Overwrite and Duplicates If you uploaded a profile with the same email or name as another existing profile but a different $distinct_id, you would create duplicates, not update the existing profile. Only the profile with the exact $distinct_id will be updated. If you import profiles using $distinct_id values that already exist, those profiles will be updated... if you upload a profile that has the same email address or the same name as another existing profile, but a different $distinct_id, you will be uploading duplicates—they will not be combined. [Importing Profiles via the UI]4. CSV Formatting Issues The documentation does not mention this explicitly, but if there are hidden formatting issues (e.g., extra spaces, invisible characters, or mismatched casing in distinct_id values), Mixpanel may not match the rows to existing profiles, resulting in missing property updates.What you can do:
- Double-check that the $distinct_id column in your CSV exactly matches the distinct_id values in Mixpanel (no extra spaces, correct casing). - Review the import process to ensure both columns were selected and mapped correctly. - Check a few of the affected profiles to see what distinct_id was set and if any new/empty profiles were created. - If the issue persists, try re-importing a small sample of the problematic rows and observe the result.If all mappings and values are correct and the issue remains, the knowledge sources do not provide further troubleshooting steps, and you may need to contact Mixpanel support for deeper investigation.References: - User Profiles FAQ - Importing Profiles via the UI
kapa.ai is still learning and improving, please let me know how I did by reacting below.
ℹ️ Tip: Mention @kapa.ai in the thread for follow-ups or DM the app for 1-to-1 help.