FULL PRODUCT VERSION :
$ ./java -version
java version "1.8.0_121"
Java(TM) SE Runtime Environment (build 1.8.0_121-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.121-b13, mixed mode)



ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 6.1.7601]


A DESCRIPTION OF THE PROBLEM :
jvm.dll file version was not updated for 8u121, but jvm.dll changed. Our software uses the Windows installer to overlay a new JRE on upgrade. Because the jvm.dll file version is the same (25.71.0.1), the 8u121 jvm.dll does not overwrite the jvm.dll file from the previous version (8u101). This causes us to get the following error when running keytool:

Invalid layout of java.lang.Thread at name
Error occurred during initialization of VM
Invalid layout of preloaded class: use -XX:+TraceClassLoading to see the origin of the problem class
"ERROR keytool failed with error: 1"

REGRESSION. Last worked in version 8u102

ADDITIONAL REGRESSION INFORMATION:
java version "1.8.0_101"
Java(TM) SE Runtime Environment (build 1.8.0_101-b13)
Java HotSpot(TM) 64-Bit Server VM (build 25.101-b13, mixed mode)

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Install jre 8u121 and 8u101 on windows and compare File Version. Replace 8u121 jvm.dll with 8u101 jvm.dll. Run keytool -list and confirm that error shows up

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
With the same file version, would expect the binaries to be the same and interchangeable. keytool -list should not show the error
ACTUAL -
./keytool.exe -list
Invalid layout of java.lang.Thread at name
Error occurred during initialization of VM
Invalid layout of preloaded class: use -XX:+TraceClassLoading to see the origin of the problem class

ERROR MESSAGES/STACK TRACES THAT OCCUR :
Invalid layout of java.lang.Thread at name
Error occurred during initialization of VM
Invalid layout of preloaded class: use -XX:+TraceClassLoading to see the origin of the problem class
"ERROR keytool failed with error: 1"

REPRODUCIBILITY :
This bug can be reproduced always.