NoClassDefError: processing/core/PApplet when starting 4.0a2 on Windows 10

[processing-bot]

Created by: mediajolt001

Description

Processing is crashing on launch and brings up the error attached here.

Expected Behavior

Expecting Processing to launch

Current Behavior

Won't launch - gives an error immediately

Steps to Reproduce

Launching Processing 4 from Windows Explorer

Your Environment

• Processing version: 4.0.2a
• Operating System and OS version: Windows 10 Home 64bit v.20H2
• Other information: Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz 4.00 GHz
  32.0 GB RAM

Possible Causes / Solutions

Possibly installing newer version of Java?

[processing-bot]

Created by: benfry

Check to see if Windows Defender has removed core.jar from the Processing folder. Seems that it decides that the file is malware and just gets rid of it.

[processing-bot]

Created by: benfry

Resolved this for 4.0 alpha 5 by catching the error (missing core.jar) and showing a more useful message.

[processing-bot]

Created by: github-actions[bot]

This issue has been automatically locked. To avoid confusion with reports that have already been resolved, closed issues are automatically locked 30 days after the last comment. Please open a new issue for related bugs.