Hi Steve, this is your problem:
java was started but returned exit code = -805306369
a) This happens when mostly corrupted workspace osgi cache.
A solution is to switch the workspace to a new location and import all projects from previous workspace. Additionally, reinstall Eclipse.
Another solution is to run Eclipse with the '-clean' parameter as:
eclipse.exe -clean
After some time, Eclipse should clean up, the workspace selection dialog should pop up so you should be able to start Eclipse normally. The '-clean' parameter is documented in the eclipse help.
A bit more troubleshooting here:
https://spacetech.dk/eclipse-failed-java-was-started-but-returned-exit-code-805306369.html
If you get this error when the workspace already set up, type on the CMD the command as follows
java -version
In case the answer is
"Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit."
try to restart your machine;
b) Sometimes one of the class file/ multiple class files in a project was/were corrupted.
c) Feel free to take a look at the Eclipse logs located at <workspace_directory>/.metadata/.log searching for more detailed info.