Corrupted workspace state on restart

Every so often, when I close VS Code and I open it again later to continue working on the project, the Java Language Server (or some part of this extension) gets a corrupted build state. All my Java files get red-lined everywhere especially with imports (which should have been resolved correctly through Maven dependencies). It makes the entire Java project riddled with errors, when there should be 0 errors reported.

The workspace log file reports:
message: The project was not built since the source file /jdt.ls-java-project/src/com/example/package/SampleClass-6b2da599__18012WV3rlaskH3xV.java could not be read;code: 0

It looks like some kind of weird diff version of the original class file (perhaps generated from all the diffing I do while I work on my project. Looks like JLS thinks the diff file is an actual project file and keeps looking for it?

I tried to look inside this jdt.ls-java-project folder but I have no idea what's wrong. The file doesn't exist. I don't know how to fix this or how to force refresh JLS cache (if there's such a thing). Any hints and pointers will be very helpful. This is the second time I am getting this problem; I don't remember how I fixed it the first time or it just fixed itself somehow.

Environment

• Operating System: Windows 10 x64
• JDK version: 1.8.0_144
• Visual Studio Code version: 1.18.1
• Java extension version: 0.15.0

Steps To Reproduce

I'm not really sure. It just randomly happens when I close VS Code and open it later again.

Current Result

Weird build errors resulting in red-lining throughout the project.

Expected Result

Successfully built project every time.

Additional Information

None.

Start with the workspace log entry and inspect the jdt.ls-java-project path mentioned in the report, especially the missing SampleClass-6b2da599__18012WV3rlaskH3xV.java file. Reproduce the close-and-reopen sequence if possible, then verify that the project rebuilds without missing-file errors or red-lined Java files.