Most viewed questions in Blockchain

0 votes
3 answers

Hyperledger-fabric not working with docker swarm

The issue is that the chaincode container ...READ MORE

Aug 20, 2018 in Blockchain by Perry
• 17,090 points
882 views
+1 vote
1 answer

Ethereum Error: authentication needed: password or unlock

First, make sure you have an account. web3.personal.listAccounts If ...READ MORE

Aug 8, 2018 in Blockchain by Omkar
• 68,840 points
882 views
+1 vote
3 answers

Hyperledger Java SDK Client Event Listener to register and listen Blocks

First add the eventhub, and then  register ...READ MORE

Oct 29, 2018 in Blockchain by Omkar
• 68,840 points
870 views
0 votes
1 answer

Truffle "Migrations" ran out of gas error

This error is caused because the amount ...READ MORE

Jan 17, 2019 in Blockchain by Omkar
• 68,840 points
865 views
0 votes
2 answers

Truffle console error: Could not find suitable configuration file

First, initialize truffle project by running: $ truffle ...READ MORE

Feb 19, 2019 in Blockchain by John
863 views
+1 vote
2 answers

Can I invoke a chaincode function from the chaincode itself?

Here's an example on how you can ...READ MORE

May 7, 2019 in Blockchain by Shir
860 views
+2 votes
2 answers

Can two chaincode interact with each other?

Yes, it is possible for two chaincodes ...READ MORE

Jul 12, 2018 in Blockchain by slayer
• 29,260 points
846 views
0 votes
1 answer

geth: Fatal: invalid genesis file: invalid character 'â' looking for beginning of object key string

Looks like your editor is adding characters ...READ MORE

Dec 5, 2018 in Blockchain by Omkar
• 68,840 points
840 views
0 votes
1 answer

Can't call contract function in truffle console

Inspect the object adoption within the console. You will ...READ MORE

Sep 28, 2018 in Blockchain by slayer
• 29,260 points
838 views
0 votes
2 answers

Hyperledger Fabric: Channel creation failed! FAILED to execute End-2-End Scenario

This error usually occurs if some old ...READ MORE

May 8, 2019 in Blockchain by John
816 views
0 votes
1 answer

Where is the hyperlewdger fabric endorsement policy stored?

I don't know exactly where is the ...READ MORE

Jul 2, 2018 in Blockchain by charlie_brown
• 7,720 points
815 views
+1 vote
8 answers

How to solve “x509: ECDSA verification failure” error?

Before you execute the  composer runtime install -c ...READ MORE

Jul 29, 2018 in Blockchain by digger
• 26,660 points
811 views
+1 vote
4 answers

What role does Orderer peer serves in Hyperledger Fabric??

Shared communication channel to clients and peers ...READ MORE

Apr 11, 2018 in Blockchain by Johnathon
• 9,090 points
795 views
0 votes
1 answer
+1 vote
4 answers

Trying to connect to Cryptocompare's websocket stream using socketIO from a Python client

The reason might be that the the socketio ...READ MORE

Aug 6, 2018 in Blockchain by Perry
• 17,090 points
784 views
0 votes
1 answer

How would I run SpringBoot with the Java-SDK of Hyperledger Fabric java daemon?

I am not familiar with SpringBoot, but ...READ MORE

Jul 3, 2018 in Blockchain by Aryya
• 7,340 points
784 views
+1 vote
1 answer

Car lease demo database location in IBM blockchain

Firstly, yes you can change the default DB ...READ MORE

Jun 7, 2018 in Blockchain by Christine
• 15,810 points
775 views
0 votes
2 answers

UnicodeDecodeError: 'utf-8' codec can't decode byte (python)

I found a python rpc library for ...READ MORE

Sep 4, 2018 in Blockchain by Piston
769 views
0 votes
1 answer

How to solve “sender doesn't have enough funds to send tx” error in Ethereum?

There’s a mistake in your code. You ...READ MORE

Jul 27, 2018 in Blockchain by slayer
• 29,260 points
769 views
0 votes
1 answer

How to force gradle to take UTF-8 encoding instead of operating system default encoding?

I've removed the UTF-8 chars from erroneous ...READ MORE

Oct 12, 2018 in Blockchain by Perry
• 17,090 points
767 views
+1 vote
2 answers

Integrating web3 from Metamask: "ReferenceError: window is not defined" error

You can't use MetaMask on server-side because ...READ MORE

Oct 10, 2018 in Blockchain by Omkar
• 68,840 points
766 views
0 votes
1 answer

NPM cannot install “truffle” on Windows

Your install is failing at node-gyp rebuild. Solutions ...READ MORE

Sep 27, 2018 in Blockchain by slayer
• 29,260 points
759 views
0 votes
1 answer

Solidity: casting address to address payable

I don’t see why direct casting isn’t ...READ MORE

Jan 23, 2019 in Blockchain by Omkar
• 68,840 points
758 views
0 votes
1 answer

What are off-chain transactions?

An off-chain transaction is the movement of ...READ MORE

Feb 12, 2019 in Blockchain by Omkar
• 68,840 points
745 views
0 votes
1 answer

How to make a class that fits Blockchain.info Json?

Hey, I found a simple solution for ...READ MORE

Sep 18, 2018 in Blockchain by digger
• 26,660 points
736 views
–1 vote
1 answer

Miner in Ethereum Private network is hanging

Looking at your commands again, I figured ...READ MORE

Jan 17, 2019 in Blockchain by Omkar
• 68,840 points
726 views
+2 votes
3 answers

Can multi-channels be supported by Hyperledger in one peer?

Yes you can run  multiple chains on ...READ MORE

Apr 10, 2018 in Blockchain by Perry
• 17,090 points
723 views
0 votes
1 answer

Hyperledger-Composer: Error: Object with ID 'undefined' in collection with ID 'chaincodes' does not exist

First delete the cache and cookies from ...READ MORE

Oct 29, 2018 in Blockchain by Omkar
• 68,840 points
721 views
+1 vote
5 answers

Hyperledger Fabric: Error cryptogen tool

I got same error on Windows.  The solution ...READ MORE

Oct 25, 2018 in Blockchain by Mahesh
721 views
0 votes
1 answer

How to reintialize genesis block in geth ethereum?

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

Dec 5, 2018 in Blockchain by Omkar
• 68,840 points
720 views
0 votes
1 answer

How to create Bitcoin Address in PHP?

You need to understand that Bitcoin address and ...READ MORE

Aug 27, 2018 in Blockchain by Perry
• 17,090 points
720 views
+1 vote
1 answer

invalid sender error when trying to send signed transaction

Hi, i had the same error and ...READ MORE

Nov 16, 2018 in Blockchain by bublig737
716 views
0 votes
1 answer

Web3 ethereum miner_start not implemented.

You have to first enable "miner" API ...READ MORE

Aug 24, 2018 in Blockchain by digger
• 26,660 points
714 views
0 votes
1 answer

var_dump of a JSON response returns NULL

You should be aware of the chances ...READ MORE

Aug 28, 2018 in Blockchain by digger
• 26,660 points
711 views
0 votes
1 answer

String concatenation in solidity?

A library can be used, for example: import "github.com/Arachnid/solidity-stringutils/strings.sol"; contract C ...READ MORE

Sep 21, 2018 in Blockchain by slayer
• 29,260 points
710 views
0 votes
1 answer

How to store data in Hyperledger Fabric after restart?

When you use docker-compose down, all the ...READ MORE

Jul 27, 2018 in Blockchain by digger
• 26,660 points
710 views
0 votes
1 answer

Not able to install truffle using npm install -g truffle

You need root access to install truffle, ...READ MORE

Nov 29, 2018 in Blockchain by Omkar
• 68,840 points
706 views
0 votes
1 answer

Hyperledger Composer: Error: Error trying to start business network. Error: No valid responses from any peers.

You have to configure TLS in peers ...READ MORE

Nov 5, 2018 in Blockchain by Omkar
• 68,840 points
698 views
+1 vote
3 answers

How to resolve the hyperledger fabric versions set up?

How to simple way to upgrade the ...READ MORE

Dec 18, 2018 in Blockchain by anonymous
695 views
0 votes
1 answer

Hyperledger Fabric CA "Failed to get user: User not found"

The problem could be because of the ...READ MORE

Jul 23, 2018 in Blockchain by digger
• 26,660 points
695 views
0 votes
1 answer

Hyperledger Fabric: Upgrading Chaincode after modification

You need to specify the channel name ...READ MORE

Nov 13, 2018 in Blockchain by Omkar
• 68,840 points
693 views
0 votes
1 answer

Solidity Web3js: Invalid number of arguments to Solidity function error

Try this: Change console.log(formData.destinationtoke); console.log(formData.amounttoke); var tx = sendtoken(destinationtoke, amounttoke); To : console.log(formData.destinationtoke); console.log(formData.amounttoke); var ...READ MORE

Oct 22, 2018 in Blockchain by Omkar
• 68,840 points
685 views
0 votes
1 answer

Hyperledger — how to set up REST API for invoking Chaincode?

Hyperledger Fabric v1.0 and later does not ...READ MORE

Nov 16, 2018 in Blockchain by Christine
• 15,810 points
681 views
0 votes
2 answers

How to generate ethereum qr code address with amount?

You implement this package: ethereum-qr-code. It implements the EIP67 standard which uses ...READ MORE

Sep 6, 2018 in Blockchain by Omkar
• 68,840 points
680 views
+1 vote
4 answers

What is hf.Registrar.Roles in fabric-ca-client command?

The "hf.Registrar.Roles" attribute is used to control ...READ MORE

Jul 11, 2018 in Blockchain by slayer
• 29,260 points
677 views
0 votes
1 answer

How to get return value from solidity contract?

Once you call a constant function, you ...READ MORE

Aug 16, 2018 in Blockchain by slayer
• 29,260 points
675 views
0 votes
1 answer

geth attach command showing error: bind: address already in use

Seems like there is already a geth instance ...READ MORE

Jan 16, 2019 in Blockchain by Omkar
• 68,840 points
672 views
0 votes
1 answer

Hyperledger Fabric: PEM encoded certificate is required.

Hey, the syntax you are using is ...READ MORE

Nov 5, 2018 in Blockchain by Omkar
• 68,840 points
671 views