Teammates: Server error when add new instructor by admin

[Derek-Hardy]

• Environment: master branch at commit 2918cc169ceb9f6d585c1cc6d645b9a6f2ea7593
• Browser: Google Chrome

• Server: dev server listening at localhost:8080

• Issue 1: action to add instructor fails at http://localhost:8080/web/admin/home
  

• Error message:

Caused by: java.lang.ClassNotFoundException: javax.activation.DataSource
        at java.base/java.net.URLClassLoader.findClass(URLClassLoader.java:466)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:563)
        at com.google.appengine.tools.development.IsolatedAppClassLoader.loadClass(IsolatedAppClassLoader.java:208)
        at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:496)
        ... 65 more

However, the new instructor can still be found at http://localhost:8080/web/admin/search

• Issue 2: the join link does not work when entered as URL.

Following the warning, either I log in through instructor login button or masquerade mode, the error occurs.

• Problem: due to the above issues, I am not able to interact with the application in instructor/student mode in the dev server.

• Setup status:

  • front & back-end are built successfully
  • run component test with 5 failed test cases
  • staging server is not yet deployed

[ccyccyccy]

Are you using JDK 8? I faced a similar problem as well when I used JDK 11.

[Derek-Hardy]

Many thanks to @ccyccyccy !

Cause: mismatched JDK (local: Java SE 9.0.1)

Solution: (for Mac OS X)

• run /usr/libexec/java_home -V on the terminal
• look for the path for Java SE 8 (Mac default version) /Library/Java/JavaVirtualMachines/jdk1.8.0_144.jdk/Contents/Home (in my case)
• in the root directory of the project, open gradle.properties, paste the line org.gradle.java.home=/Library/Java/JavaVirtualMachines/jdk1.8.0_144.jdk/Contents/Home
• open a new terminal, cd to the project folder, re-run the command ./gradlew createConfigs

Result:
The above solution resolves the issue.

[Derek-Hardy]

Server error issue is resolved.