git-plugin does not cause this error

Git plugin:
Global Config user.name Value - null
Global Config user.email Value - null
Create new accounts based on author/committer's email - False

1. Prerequisite:

master Jenkins ver. 2.43 , jdk1.8.0_112, Windows2008R2
slave1 - jdk1.7.0_51, RHEL 6.5
slave2 - jdk1.7.0_51, RHEL 6.5

2. Create:
job1 Freestyle project(For Example: Empty job or add Shell Execute Block: sleep 300, gradle build)

3. Update Jenkins:
master to ver. 2.60.1, jdk1.8.0_112
slave1 - slave.jar, jdk1.8.0_112
slave2 - slave.jar, jdk1.8.0_112

4. Configure slaves:
Jenkins->Nodes->slave1->Configure->Labels: LabelRunJob
Jenkins->Nodes->slave2->Configure->Labels: LabelRunJob

5. Configure job1:
Jenkins->View1->job1->Configure->Enable "This project is parameterized":
Add Label:
Name: LabelRunJob
Default Value: LabelRunJob
Disable "Run on all nodes matching the label"

6. Run job1 on slaves(parallel run job)
After 10-50 success build, get:
Caused: com.google.common.util.concurrent.UncheckedExecutionException

Workarщund:
Create new job2 copy from job1
or
Create new Node slave3 copy from slave1
and
Create new Node slave4 copy from slave2

Log and build.xml in attach