Spark hangs on Win7 log off

Hi All

I have found that Spark hangs when user logs off windows.
Only occurs if main window or logon window is open.
Does not seem to happen if only tray icon is active.

Spark.exe seems to consume full CPU (100 percent of one core…)

Win7 64, Spark 2.6.3



are you using the JRE that is installed in your OS and is this a version Java 6 u25 or above? This is a known issue of the JRE together with Spark. There are as far as I know three options:

  1. Use the Spark with the build in JRE. This is working but may be considered a security issue. However, the Spark JVM should only be used by Spark and this may be less of a problem since the JVM i snot used for applets in a browser.
  2. Upgrade your JVM to Java 7. As far as I know, the Java issue is not existing in J7.
  3. Downgrade your OS JVM to Java6 u 24. This is not seriously an option to to security riscs for the whole system.
    Kind regards


1 Like

Thanks that worked. I installed the spark package with JRE.

Java has been an upgrade/downgrade battle for 10 years!!. Really annoying!!


which one of the three was the right one for you ?


The Java that came with the Spark package.

I uninstalled ‘spark online’ and installed the spark all-in-one package.

Just to confirm, I tried the online package again, and the log off issue returns.

My system JVM is 6, u27.

Thanks Walter

Does the known issue also affect 2.5.8? I have several Windows 7 users who complain about this issue.