# Not able to run transaction

**URL:** <https://forum.flow.com/t/not-able-to-run-transaction/1747>\
**Category:** Uncategorized\
**Created:** [April 17, 2021, 11:21am UTC](https://forum.flow.com/t/not-able-to-run-transaction/1747 "2021-04-17T11:21:22Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![shram](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.flow.com/shram/32/423_2.png) [@shram](https://forum.flow.com/u/shram)\
**Post date:** [April 17, 2021, 11:21am UTC](https://forum.flow.com/t/not-able-to-run-transaction/1747/1 "2021-04-17T11:21:23Z")

</div>

I am tryign to follow this tutorial on Medium:[How to Create NFTs Like NBA Top Shot With Flow and IPFS | by Justin Hunter | Pinata | Medium](https://medium.com/pinata/how-to-create-nfts-like-nba-top-shot-with-flow-and-ipfs-701296944bf)

When I generate the private keys and add it to flow.json and then try to run the transaction I get an error:  
❌ Config Error: invalid project configuration: input has incorrect ECDSA\_P256 key size

My flow.json is as below:

```
{
	"emulators": {
		"default": {
			"port": 3569,
			"serviceAccount": "emulator-account"
		}
	},
	"contracts": {"AFTContract": "./cadence/contracts/AFTContract.cdc"},
	"networks": {
		"emulator": {
			"host": "127.0.0.1:3569",
			"chain": "flow-emulator"
		},
		"mainnet": {
			"host": "access.mainnet.nodes.onflow.org:9000",
			"chain": "flow-mainnet"
		},
		"testnet": {
			"host": "access.devnet.nodes.onflow.org:9000",
			"chain": "flow-testnet"
		}
	},
	"accounts": {
		"emulator-account": {
			"address": "f8d6e0586b0a20c7",
			"privateKey": "1531c101b69c4c6d37124cea949b627d051b8f0bb66117a71c834e4bd5e29a63",
			"sigAlgorithm": "ECDSA_P256",
     		"hashAlgorithm": "SHA3_256",
			 "chain": "flow-emulator"
		}
	},
	"deployments": {
		"emulator": {
		"emulator-account": ["AFTContract"]
   }}
}

```

What am i doing worng?

---

<div class="post-metadata">

**Author:** ![shram](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.flow.com/shram/32/423_2.png) [@shram](https://forum.flow.com/u/shram)\
**Post date:** [April 17, 2021, 4:28pm UTC](https://forum.flow.com/t/not-able-to-run-transaction/1747/2 "2021-04-17T16:28:52Z")

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I had removed the “Keys” entry for flow.json. Working when I put that back in.

---

<div class="post-metadata">

**Author:** ![anders](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@anders](https://forum.flow.com/u/anders)\
**Post date:** [May 23, 2021, 5:06pm UTC](https://forum.flow.com/t/not-able-to-run-transaction/1747/3 "2021-05-23T17:06:13Z")

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I have the same issue. Did you manage to solve it?

EDIT:  
Never mind! I just realized I had pasted the public keys, instead of the private ones in flow.json. Works now.