ZCash Desktop GUI Wallet


Hello everyone,
Zcash server is running and I moved ZCashSwingWalletUI.jar in zcash/src folder and now I cant start the wallet when I double click on it!

Any ideas ?
Thanks in advance !


Yes, I can see the 0.00989137 ZEC on my wallet GUI.
Thank you very much mista66 and vaklinov ^_^.


Please check if the ZCashSwingWalletUI.jar is executable. If necessary repeat the command:
chmod u+x ZCashSwingWalletUI.jar
in zcash/src folder. If it still does not start by double click, or by right click + "Open with OpenJDK 8 Runtime", then please try to start it from terminal:
java -jar ZCashSwingWalletUI.jar
and if it again fails to start, write to me via messaging and show me the terminal log... maybe there is some error condition that has happened.


Thank you for your reply !
Here is the terminal log :

Starting ZCash Swing Wallet ...
OS: Linux = LINUX
Current directory: /home/jumparo/zcash/src
Class path: ZCashSwingWalletUI.jar
Environment PATH: /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
Available look and feel: Metal javax.swing.plaf.metal.MetalLookAndFeel
Available look and feel: Nimbus javax.swing.plaf.nimbus.NimbusLookAndFeel
Using ZCash utilities: zcashd: /home/jumparo/zcash/src/zcashd, zcash-cli: /home/jumparo/zcash/src/zcash-cli

A fatal error has been detected by the Java Runtime Environment:

SIGSEGV (0xb) at pc=0x00007f188b9d9009, pid=2737, tid=2738

JRE version: OpenJDK Runtime Environment (9.0) (build 9-internal+0-2016-04-14-195246.buildd.src)
Java VM: OpenJDK 64-Bit Server VM (9-internal+0-2016-04-14-195246.buildd.src, mixed mode, tiered, compressed oops, serial gc, linux-amd64)
Problematic frame:
C [libjava.so+0x1d009] JNU_GetEnv+0x19

Core dump will be written. Default location: Core dumps may be processed with "/usr/share/apport/apport %p %s %c %P" (or dumping to /home/jumparo/zcash/src/core.2737)

An error report file with more information is saved as:

If you would like to submit a bug report, please visit:
The crash happened outside the Java Virtual Machine in native code.
See problematic frame for where to report the bug.

Aborted (core dumped)


You seem to be using JDK 9 - it is not officially released and is unstable. You need to use JDK 8. See also this report of the same type: http://askubuntu.com/questions/791021/unable-to-open-jar-files-with-java

One proposed fix is:

sudo apt-get remove openjdk-9-*
sudo apt-get install default-jdk

What version of Ubuntu (or other Linux) have you got? How did you install Java?


I followed this tutorial : https://www.cryptocompare.com/wallets/guides/how-to-install-the-zcash-gui-wallet
I am using ubuntu 16.04 64 bit.
I did these commands :

sudo apt-get remove openjdk-9-*
sudo apt-get install default-jdk

it removed openjdk9 but then it shows that nothing new is installed nor upgraded.


Strange: When using ubuntu 16.04, the default-jdk should install JDK 8, not 9. What is the output of command:
java -version
it should show a version 1.8.x like:

openjdk version "1.8.0_111"
OpenJDK Runtime Environment (build 1.8.0_111-8u111-b14-2ubuntu0.16.04.2-b14)
OpenJDK 64-Bit Server VM (build 25.111-b14, mixed mode)


Another way to re-install Java on Ubuntu and be sure yo have JDK 8 is:

sudo apt-get remove openjdk*
sudo apt-get install openjdk-8-jdk ant

Since the GUI wallet may have been built with JDK 9 - it is a good idea to rebuild it...


I rebuild it and reinstall JDK 8 and everything is fine! Thank you a lot for the help !


Hi Vaklinov

just wondering, will this gui wallet work with ZCasslic?

if not can you adjust it so it does?



There is already a fork of the GUI wallet by another GitHub developer:

that is intended to work with zclasic. The only change for now seems to be that the block-chain dir. has changed from ~/.zcash to ~/.zclassic I am not sure it works but you may try it ...

BTW: I have reservations about zclassic due to the need for a trusted setup!


Exactly. Its amazing people think just forking code gives their effort value. The reason Zcash is valuable has to do with the reputations of the team behind it. If they were to do anything bad then their reputations in the community would suffer as would the ZCash price.

Zclassic on the other hand has nothing to lose if its developers (who are they!?) decided to keep the toxic waste and use it to scam everyone.


cool thanks for the link

but since they forked ZCash, are they not depending on ZCash's trusted set up?
ie if ZCash developers did not delete their initial block info, wouldn't they be able to create more ZClassic along with more ZCash? wouldn't they hold the keys to both?

was it launched from scratch again? i thought they just forked off of the existing ZCash blockchain,... but then I was wondering how htey got rid of the funders fee if that is what they did

AND if its a bad thing, why would zook say its a good thing?


From the code diffs I saw initially I think they were just removing the sending of the FR as part of the block reward, but I didn't look closely enough to see if the did a new trusted setup or not.


You are right: ZClassic claims to use the the exact same trusted setup keys as ZCash:


cool, so ZCash could have the key to both ZCash and ZCLassic, so its safe :slight_smile: as safe as trust in zooko - so safe

thanks for the link


I've known Zooko and Daira for nearly 15 years online, so I myself am inclined to trust them. Of course that's just a valid belief for me based on my experiences, but I think that decades of public mailing list archives show him to be someone with very high ethical standards.


zooko seems real
maybe you can get me an interview with one of them soon :slight_smile:
like 15 min online Q&A :slight_smile:


Sure, I can give it a whirl sometime....he practically lives on twitter, and depending on what he's doing in offline reality he often replies to me over there nearly instantly (well, that or a day or 2 later! :slight_smile: )

Would the interview be for a post on your pool's blog or something?


LOL, well would make for a good video on youtube, thats for sure