Mixpanel Community Icon

Home
Groups
Members

Announcements
Community Questions
Mixpanel Bot
Product Ideas
Resources

Community Guidelines

Docs & Guides
Events & Webinars
Contact Us

Powered by Tightknit

Community Questions

Community Questions

Mixpanel Integration Issues: 'Not Set' Data on Events

·Sep 04, 2025 06:41 PM·

Hey team! I recently added Mixpanel to both our mobile app and website. Noticed a couple of issues:

Operating System is showing up as 'not set' on the web event
Location (Country/City) is coming through as 'not set' for some events

Any idea what could be causing this, and how I can fix it?

3 comments

· Sorted by Oldest

Julianne Bozzini
APP
·
·
Hi Isha- Julianne from Mixpanel Support here! The expected behavior for default properties depends on the SDK being used. For example, server-side SDKs wouldn't be expected to capture the 'Operating System'. The geolocation behavior can also vary depending on the client vs server-side SDK. Which SDK(s) was implemented for the events here?
Isha V.
·
·
We have implemented both - server side and client side(as fallback) Is there a way I can enable capturing Operating System in server side SDK?
Julianne Bozzini
APP
·
·
Yes, you can capture the 'Operating System' in server-side SDKs! You'll just need to implement it on your end since it isn't a default property. The Server-Side Best Practices guide has a ton of great information and examples about capturing that property, along with others. If you want the server-side property to be included in the same breakdowns as the client-side SDK properties, you'll need to set the server-side event property name to the same as the client-side raw names found here. So, for example, 'Operating System' should be sent with an event property name of $os.