Why does my new Mark II or Structure Sensor Pro say "Please Connect Structure Sensor"? It IS connected!

There are multiple reasons why you may be experiencing connectivity issues.

Generally speaking, the best practice for initializing your sensor is to launch your app first with the sensor already disconnected. When prompted, connect your sensor. Initialization may take up to five seconds.

Didn't work?

There are other reasons this may be the case.


Your firmware is not up to date.

With the release of firmware version 1.2 and SDK 1.2, virtually all cable connectivity issues were solved.

To make sure your firmware is up to date, please follow check out this article: https://support.structure.io/article/410-getting-started---updating-your-sensors-firmware

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Your apps are not up to date.

This is coupled with the firmware update--apps that are still running SDK 0.11 will continue to have connectivity problems. All of our first-party apps are built on the current SDK, and as such, you simply need to make sure to update your apps. 

To manually update your apps, please follow these instructions by Apple: https://support.apple.com/en-us/HT202180

If you are using a third-party app, we still recommend checking if there is an update. If not, please contact that specific developer for support.

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Your app has not been updated to work with Mark II or Structure Sensor Pro.

Apps that have not been upgraded to specifically work with Mark II or Structure Sensor Pro will ask you to connect to Structure Sensor or to ask you to charge your Structure Sensor. For a list of updated apps, please check out this article.

If you have a particular app that you require that is not on the list, we ask that you contact that developer directly for estimated availability date.

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Your sensor may need to charge.

Your sensor may have initialization trouble if the battery is too low. Please make sure to fully charge your sensor before use.

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You may have a cable issue.

If you have tried everything else and it still seems as though your sensor will not initialize no matter what, there may be an issue with the cable.

The first step in the troubleshooting process is always a hard restart of your iOS device:

  • Instructions: Restart your iOS device
  • Explanation: On occasion, iOS needs a hard restart to be able to recognize the device properly again.

Next, make sure there is a clear connection between your Structure Sensor and iOS device:

  • Check the charging port at the bottom of your iOS device for damage and/or debris
  • Check the Lightning/USB-C Connector Cable ends for any foreign substances, and clean both ends of the cable with rubbing alcohol
  • Explanation: Interference/debris on the connectors can cause the cable to appear not to work.

Finally, try the following:

  • Model ST01 - Plug the AC adapter into the sensor, then plug the sensor into your iPad. Next, go to Settings -> General -> About -> (Do you see Structure Sensor below Bluetooth?)
  • Model ST02A - Plug the sensor into your iPad. Next, go to Settings -> General -> About -> (Do you see Structure Sensor below Bluetooth?)
  • If you have another iPad/iPhone you can test with your sensor? If yes -> After you plug in the sensor go to Settings -> General -> About -> (Do you see Structure Sensor below Bluetooth?)
  • Explanation: ST02A - If the sensor shows up 90% of the time this means the cable is working if it does not show up on either device then it means there is a cable issue. If it shows up on one device and not the other this usually means one of the previous steps can resolve the issue.
  • Explanation: ST01 - If the sensor shows up with the AC adapter plugged in this means that there is likely to be a battery issue with the sensor.

If you have another cable available to test with, we suggest trying the above steps with that cable.

If you purchased your cable within the last 90 days, you may be eligible for a warranty cable replacement. Please email support for more information. 

If you purchased your cable outside of the 90-day mark, it is no longer eligible for a warranty replacement. Instead, replacement cables may be purchased from our accessories page.

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None of these work?

Please email support for further options.

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