# "Could not claim core" **URL:** \ **Category:** Troubleshooting\ **Created:** [December 27, 2013, 6:12pm UTC](https://community.particle.io/t/could-not-claim-core/1033 "2013-12-27T18:12:58Z")\ **Posts on this page:** 16\ **Page:** 2
**Author:** ![kevin\_1](https://avatars.discourse-cdn.com/v4/letter/k/f1d935/32.png) [@kevin\_1](https://community.particle.io/u/kevin_1)\ **Post date:** [March 30, 2014, 9:42pm UTC](https://community.particle.io/t/could-not-claim-core/1033/21 "2014-03-30T21:42:40Z")
Thanks for the help Dave. All is good now. ---
**Author:** ![hirotakaster](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/hirotakaster/32/2223_2.png) [@hirotakaster](https://community.particle.io/u/hirotakaster)\ **Post date:** [September 1, 2014, 9:41am UTC](https://community.particle.io/t/could-not-claim-core/1033/22 "2014-09-01T09:41:11Z")
Hi, @Dave I got same problem now. After factory reset, my Spark can’t add. Can I send mail my ID to [hello@spark.io](mailto:hello@spark.io)? ---
**Author:** ![Dave](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/dave/32/181_2.png) [@Dave](https://community.particle.io/u/Dave)\ **Post date:** [September 1, 2014, 3:16pm UTC](https://community.particle.io/t/could-not-claim-core/1033/23 "2014-09-01T15:16:38Z")
Hi @hirotakaster, Yup! 🙂 Thanks, David ---
**Author:** ![hirotakaster](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/hirotakaster/32/2223_2.png) [@hirotakaster](https://community.particle.io/u/hirotakaster)\ **Post date:** [September 2, 2014, 1:04am UTC](https://community.particle.io/t/could-not-claim-core/1033/24 "2014-09-02T01:04:01Z")
Hi @Dave, Thank you!! I send my ID to [hello@spark.io](mailto:hello@spark.io), please check it. ---
**Author:** ![GreenStone](https://avatars.discourse-cdn.com/v4/letter/g/a87d85/32.png) [@GreenStone](https://community.particle.io/u/GreenStone)\ **Post date:** [October 29, 2014, 8:44pm UTC](https://community.particle.io/t/could-not-claim-core/1033/25 "2014-10-29T20:44:49Z")
I am experiencing the same issue. The app can not find any cores in the network (tried removing the password, firewall). And if I setup the core manually over the USB I can get it to flash cyan but using the ID in the Web IDE returns the error “Could not claim core”. Hope you can help me out with this issue. I tried the procedure in Chrome 64 bit and then also Firefox. Best regards, GreenStone ---
**Author:** ![kennethlimcp](https://avatars.discourse-cdn.com/v4/letter/k/c0e974/32.png) [@kennethlimcp](https://community.particle.io/u/kennethlimcp)\ **Post date:** [October 29, 2014, 9:43pm UTC](https://community.particle.io/t/could-not-claim-core/1033/26 "2014-10-29T21:43:07Z")
Hey there, Is the core blinking cyan or breathing cyan? Blinking cyan means the core is connected to the WiFi network but is trying to reach the spark ☁ The core will have to be in breathing cyan, indicating that it’s online before claiming can happen 🙂 ---
**Author:** ![GreenStone](https://avatars.discourse-cdn.com/v4/letter/g/a87d85/32.png) [@GreenStone](https://community.particle.io/u/GreenStone)\ **Post date:** [October 29, 2014, 10:44pm UTC](https://community.particle.io/t/could-not-claim-core/1033/27 "2014-10-29T22:44:14Z")
Well, how slow is the breathing? Because there are two types of cyan blinking. However, I would not describe those as breathing, more a fast and slow blinking. ---
**Author:** ![kennethlimcp](https://avatars.discourse-cdn.com/v4/letter/k/c0e974/32.png) [@kennethlimcp](https://community.particle.io/u/kennethlimcp)\ **Post date:** [October 29, 2014, 10:45pm UTC](https://community.particle.io/t/could-not-claim-core/1033/28 "2014-10-29T22:45:03Z")
It should work like this: [https://vine.co/v/hFdxB9lHOmv](https://vine.co/v/hFdxB9lHOmv) ---
**Author:** ![GreenStone](https://avatars.discourse-cdn.com/v4/letter/g/a87d85/32.png) [@GreenStone](https://community.particle.io/u/GreenStone)\ **Post date:** [October 29, 2014, 10:48pm UTC](https://community.particle.io/t/could-not-claim-core/1033/29 "2014-10-29T22:48:17Z")
Thanks for the video! The blinking here is faster, which means that Spark was able to connect to the internet. But it quickly turns into yellow fast flashing and at some point red. I’ve removed the password from my network to make the access easiert. But still the same result. ---
**Author:** ![kennethlimcp](https://avatars.discourse-cdn.com/v4/letter/k/c0e974/32.png) [@kennethlimcp](https://community.particle.io/u/kennethlimcp)\ **Post date:** [October 29, 2014, 10:50pm UTC](https://community.particle.io/t/could-not-claim-core/1033/30 "2014-10-29T22:50:23Z")
It sounds like a bad keys if you see flash flashing yellow/red. You can use `Spark-cli` to repair this in DFU-mode with `spark keys doctor core_id` ---
**Author:** ![GreenStone](https://avatars.discourse-cdn.com/v4/letter/g/a87d85/32.png) [@GreenStone](https://community.particle.io/u/GreenStone)\ **Post date:** [October 29, 2014, 10:52pm UTC](https://community.particle.io/t/could-not-claim-core/1033/31 "2014-10-29T22:52:08Z")
Ok, I will try to make it work in DFU mode. But first I will need to read up on that. Thanks, Kenneth! I will report back whether it worked. ---
**Author:** ![GreenStone](https://avatars.discourse-cdn.com/v4/letter/g/a87d85/32.png) [@GreenStone](https://community.particle.io/u/GreenStone)\ **Post date:** [October 30, 2014, 10:21pm UTC](https://community.particle.io/t/could-not-claim-core/1033/32 "2014-10-30T22:21:56Z")
Hi Kenneth, I tried to get spark-cli to work and execute the spark keys doctor core\_id command. This is the result: ![](https://community.particle.io/uploads/particle/3434/ed36149b586ee81d.jpg) Unfortunately the key remained the same. Do you have any other suggestions? Best regards, GreenStone ---
**Author:** ![kennethlimcp](https://avatars.discourse-cdn.com/v4/letter/k/c0e974/32.png) [@kennethlimcp](https://community.particle.io/u/kennethlimcp)\ **Post date:** [October 30, 2014, 10:33pm UTC](https://community.particle.io/t/could-not-claim-core/1033/33 "2014-10-30T22:33:24Z")
Is your `Spark cli` the latest version? I think you did not change **core\_id** to your actual core ID!! 😉 ---
**Author:** ![GreenStone](https://avatars.discourse-cdn.com/v4/letter/g/a87d85/32.png) [@GreenStone](https://community.particle.io/u/GreenStone)\ **Post date:** [October 30, 2014, 10:48pm UTC](https://community.particle.io/t/could-not-claim-core/1033/34 "2014-10-30T22:48:55Z")
Yes, you are right 😃 I realized my mistake with the core\_id after I looked into manually flashing the core. Which I managed btw 😉 And now after the spark keys doctor command with core ID…it works!! Thanks, Kenneth! That was a great learning experience and would not have been possible without your help 😃 Thank you very much! ---
**Author:** ![dhruvsakalley](https://avatars.discourse-cdn.com/v4/letter/d/dec6dc/32.png) [@dhruvsakalley](https://community.particle.io/u/dhruvsakalley)\ **Post date:** [February 15, 2015, 10:10pm UTC](https://community.particle.io/t/could-not-claim-core/1033/35 "2015-02-15T22:10:29Z")
I’m having the same issue, I cannot claim my core. My problem is slightly different from the ones mentioned above, When I try putty, i I get my core id, when I do a ‘w’ from the listening mode (blinking blue) it goes to blinking green and then breathing cyan signalling it has connected to the cloud, but the putty serail does not respond to any further commands. If I close putty and try to reconnect the behavior is same, session is open but the core is unresponsive. When I try with the android app, core does accept the ssid and password and turns to breathing cyan but android app signals could not find core. While attempting the same on Web IDE I get the message could not claim core, even though it is connected to the cloud. I see there are posts resolving similar issues, but I do not understand what the resolution was or what was creating this problem. I will email my code id to mentioned email. Thanks, Dhruv ---
**Author:** ![kennethlimcp](https://avatars.discourse-cdn.com/v4/letter/k/c0e974/32.png) [@kennethlimcp](https://community.particle.io/u/kennethlimcp)\ **Post date:** [February 15, 2015, 11:26pm UTC](https://community.particle.io/t/could-not-claim-core/1033/36 "2015-02-15T23:26:20Z")
Can you perform a factory reset and try again? [Previous page](https://community.particle.io/t/could-not-claim-core/1033.md?page=1)