Most viewed questions in Blockchain

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Docker on mac error message can't connect to Docker endpoint

While CORE_VM_ENDPOINT set to unix:///var/run/docker.sock, please make sure that var/run/docker.sock exists in ...READ MORE

Sep 19, 2018 in Blockchain by slayer
• 29,350 points
1,924 views
+1 vote
1 answer

Can we copy a smart contract?

While the contract is open-source, if you ...READ MORE

Apr 7, 2018 in Blockchain by Christine
• 15,790 points
1,921 views
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1 answer

What are the differences between chain and state database in hyperledger fabric?

There are two place which "store" data ...READ MORE

Jul 11, 2018 in Blockchain by Shashank
• 10,400 points
1,913 views
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1 answer

Ethereum smart contract event trigger notification

I have an example here for web3js ...READ MORE

Aug 1, 2018 in Blockchain by slayer
• 29,350 points
1,908 views
0 votes
1 answer

truffle compile shows error: TypeError: Invalid type for argument in function call.

You are getting this error because you ...READ MORE

Dec 5, 2018 in Blockchain by Omkar
• 69,210 points
1,901 views
0 votes
1 answer

Unable to unmarshal non-string into Go struct field SendTxArgs from of common.Address

Probably you should specify the default_account for client(sender address). In my ...READ MORE

Aug 28, 2018 in Blockchain by Johnathon
• 9,090 points
1,901 views
0 votes
1 answer

How to join a peer to a channel in Hyperledger Fabric?

When you run the command: peer channel create ...READ MORE

Jul 31, 2018 in Blockchain by digger
• 26,740 points
1,900 views
0 votes
1 answer

How to interact with a Smart Contract on private network using Web3.js?

Once you set up infura you can ...READ MORE

Aug 22, 2018 in Blockchain by Christine
• 15,790 points
1,896 views
0 votes
1 answer

eth.getTransactionReceipt returns null

It looks like there's an issue with ...READ MORE

Sep 25, 2018 in Blockchain by slayer
• 29,350 points
1,894 views
0 votes
1 answer

Not able to install truffle-contract

There’s a permission error. Run this command ...READ MORE

Jan 23, 2019 in Blockchain by Omkar
• 69,210 points
1,887 views
0 votes
2 answers

Hyperledger-fabric : chaincode deploy connection error "addrConn.resetTransport failed to create client"

I have your problem too,  PLEASE HELP ...READ MORE

Feb 28, 2019 in Blockchain by Hyperledger hater
1,887 views
+1 vote
1 answer

Why is it so difficult to find a nonce while validating a block in Bitcoin?

A nonce is just "some arbitrary number". In ...READ MORE

Apr 11, 2018 in Blockchain by Perry
• 17,100 points
1,884 views
0 votes
1 answer

How to run smart contract function using nethereum to return a result?

Try this: var result = getUserAtIndex.CallAsync<byte[]>(123) ...READ MORE

Oct 24, 2018 in Blockchain by Omkar
• 69,210 points
1,883 views
0 votes
1 answer

Intl.NumberFormat() does not show the Bitcoin Ƀ Symbol

According to bitcoin.it (https://en.bitcoin.it/wiki/Bitcoin_symbol), The ISO 4217 currency code for ...READ MORE

Aug 27, 2018 in Blockchain by slayer
• 29,350 points
1,878 views
0 votes
1 answer

How to set web3 solidity variable value?

The setLog transaction has not yet been mined by ...READ MORE

Jul 6, 2018 in Blockchain by Christine
• 15,790 points
1,868 views
0 votes
1 answer

Python Script to pull data from Blockchain JSON

Try this: print r.json()['address'],' has ', r.json()['n_tx'], 'tr ...READ MORE

Sep 14, 2018 in Blockchain by digger
• 26,740 points
1,863 views
0 votes
1 answer

What is the use of Ethereum's RLPx in Ethereum ecosystem?

So, RLPx is a protocol suite. It ...READ MORE

Jun 5, 2018 in Blockchain by Johnathon
• 9,090 points
1,860 views
0 votes
1 answer

Truffle npm run dev throws Error: npm ERR! Linux 4.15.0-39-generic

The json file required to run dev is ...READ MORE

Dec 1, 2018 in Blockchain by Omkar
• 69,210 points
1,857 views
0 votes
1 answer

How to Query hdfs with Spark Sql

Yyou can achieve this by creating Dataframe. val ...READ MORE

Sep 20, 2018 in Blockchain by slayer
• 29,350 points
1,855 views
0 votes
1 answer

Not able to install truffle

This error occurs when there are permission ...READ MORE

Jan 29, 2019 in Blockchain by Omkar
• 69,210 points
1,847 views
+1 vote
1 answer

hyperledger fabric: can't find package: github.com/pkg/errors in GOPATH or GOROOT

Hey @aiga, try to add the package ...READ MORE

Aug 5, 2019 in Blockchain by Esha
1,845 views
0 votes
1 answer

How to create channels in Hyperledger Sawtooth?

There are two features that I know ...READ MORE

Aug 9, 2018 in Blockchain by slayer
• 29,350 points
1,842 views
0 votes
1 answer

Ethereum call contract method that emits an event, from another contract

You need to refer to the EventEmitter by ...READ MORE

Sep 25, 2018 in Blockchain by digger
• 26,740 points
1,841 views
+1 vote
1 answer

Can't instantiate any chaincodes on peers of newly Added org

Seems like chaincode install may have been unsuccessful. Before ...READ MORE

Sep 20, 2018 in Blockchain by Perry
• 17,100 points
1,837 views
0 votes
1 answer

Test ethereum Event Logs with truffle

You are passing tx hash into done() ...READ MORE

Sep 21, 2018 in Blockchain by slayer
• 29,350 points
1,824 views
+1 vote
1 answer

How to install Hyperledger Composer on Linux?

You need some pre-requisites to install Hyperledger ...READ MORE

Mar 1, 2019 in Blockchain by Avanti
1,822 views
0 votes
1 answer

How to install Ethereum Blockchain on Linux?

To install Ethereum on Linux, open the ...READ MORE

Feb 28, 2019 in Blockchain by Kruti
1,821 views
0 votes
1 answer

How to read a state after writing it into a chaincode?

Data that is 'written' in chaincode is ...READ MORE

May 28, 2018 in Blockchain by Perry
• 17,100 points
1,821 views
0 votes
1 answer

How to create a Genesis Block in a Private Network?

{     "nonce": "0x0000000000000042",     "difficulty": "0x000000100",     "alloc": {     },     "mixhash": "0x0000000000000000000000000000000000000000000000000000000000000000",     "coinbase": "0x0000000000000000000000000000000000000000",     "timestamp": "0x00",     "parentHash": ...READ MORE

Jul 12, 2018 in Blockchain by digger
• 26,740 points
1,804 views
+1 vote
1 answer

How can I connect to the specified nodes using IPFS?

You can actually connect to the specific ...READ MORE

Apr 25, 2018 in Blockchain by Christine
• 15,790 points
1,803 views
–1 vote
1 answer

geth attach Fatal: Unable to attach to remote geth: no known transport for URL scheme "c"

Seems like geth.ipc path is not set. When ...READ MORE

Jan 17, 2019 in Blockchain by Omkar
• 69,210 points
1,798 views
+2 votes
1 answer

Blockchain declining my API key and I cannot understand why.

It's quite easy. Request the API key using ...READ MORE

Apr 3, 2018 in Blockchain by Christine
• 15,790 points
1,794 views
0 votes
1 answer

Error while generating smart contracts which returns array of struct in Web3j v3.3.1

Solidity does not support returning structs in ...READ MORE

Jul 26, 2018 in Blockchain by Perry
• 17,100 points
1,792 views
0 votes
1 answer

How to create an instance of contract in Truffle console?

Hi, @There, I would suggest you go through ...READ MORE

Jun 17, 2020 in Blockchain by Gitika
• 65,910 points
1,791 views
0 votes
1 answer

How to create light wallet in Web3J?

You can use this method to create ...READ MORE

Aug 10, 2018 in Blockchain by slayer
• 29,350 points
1,786 views
0 votes
2 answers

Modifiers in solidity

pragma solidity ^0.4.17; contract ModifiersTutorial { ...READ MORE

Oct 12, 2018 in Blockchain by Pulkit
1,774 views
0 votes
1 answer

How many peers in fabric network need to endorse a transaction?

The number of peers required to endorse ...READ MORE

Jan 31, 2019 in Blockchain by Omkar
• 69,210 points
1,773 views
+1 vote
0 answers

cryptogen: error: open ./crypto-config.yaml: The system cannot find the file specified [closed]

I created a generate.sh to generate crypto ...READ MORE

Mar 1, 2019 in Blockchain by Tharindu
• 170 points

closed Mar 1, 2019 by Tharindu 1,769 views
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1 answer

Can we find out the bitcoin sender by their address?

It is not possible to find the ...READ MORE

Dec 4, 2018 in Blockchain by Omkar
• 69,210 points
1,765 views
0 votes
1 answer

How can i extract information from Ethereum blockchain using python?

Give the RPC (--rpc) option when you ...READ MORE

Jul 31, 2018 in Blockchain by Shashank
• 10,400 points
1,760 views
0 votes
1 answer

Ethereum, web3, Error: invalid argument 0: cannot unmarshal non-string as hex data, when I call a contract

I have the same problem. But with ...READ MORE

Oct 8, 2018 in Blockchain by Omkar
• 69,210 points
1,758 views
–1 vote
1 answer

User Identity Management in Ethereum using ERC725

The identity consists of two main parts: Keys ...READ MORE

Dec 28, 2018 in Blockchain by Omkar
• 69,210 points
1,756 views
0 votes
1 answer

safeTransferFrom does not transfer etherium to the target. ERC-721

I changed my contract buy function like ...READ MORE

Apr 7, 2022 in Blockchain by Rahul
• 9,670 points

edited Mar 13, 2023 by Gunashree 1,755 views
0 votes
1 answer

How to see bitcoin transaction info?

You can view foreign transactions using bitcoind. Set txindex=1 in ...READ MORE

Aug 17, 2018 in Blockchain by digger
• 26,740 points
1,754 views
0 votes
1 answer

How to access bitcoin Daemon from other services?

You don't need all these things to ...READ MORE

Aug 29, 2018 in Blockchain by digger
• 26,740 points
1,753 views
0 votes
1 answer

How to handle smart contract transaction express nodejs?

sendSignedTransaction returns a Promise combined event emitter. You can ...READ MORE

Oct 15, 2018 in Blockchain by Omkar
• 69,210 points
1,746 views
0 votes
1 answer

Truffle init: Error: Cannot find module 'original-require'

I think you need to run this ...READ MORE

Oct 24, 2018 in Blockchain by Omkar
• 69,210 points
1,743 views
0 votes
1 answer

Ethereum: functions Burn and Transfer source

This statement is used to publish an event that ...READ MORE

Oct 9, 2018 in Blockchain by Omkar
• 69,210 points
1,741 views
0 votes
1 answer

How to get value from solidity contract using java?

web3j caters for this very use case. It ...READ MORE

Sep 28, 2018 in Blockchain by slayer
• 29,350 points
1,741 views