I was developing a plugin, using Eclipse IDE for java developers (Version: 2021-09 (4.21.0) Build id: 20210910-1417)
During development, when I run it as an eclipse application, it opens a runtime-Eclipse application where the plug-in is present. In my setup this new runtime-eclips app opened from a folder next to the workspace, where C codes were present. (and my progrem would get the tests run in C , and get the results from it's exe)
Then I downloaded the Eclipse IDE for committers, which is a newer version. I downloaded it as a zip and after unpacking I run the eclipse.exe. My program had problems opening the runtime-Eclipse application in C there, so i went back to the older one which is installed on my computer.
After opening the original eclipse, on which I was working and had no problems, I was hoping everything will be fine. It opens the IDE for java developers (same version, same build) but I have the same problems with the runtime-eclipse application as the one I run as an eclipse.exe , (not recognising the C code?? I don't understand).
When i try to run the plug-in I get this error.
And when the runtime-app opens i get this error.
I cannot create C projects anymore on the runtime-app. I don't know the reason behind this. 
Also I have billion of these ["java.net.UnknownHostException: downdload.eclipse.ort"] [" org.eclipse.equinox.p2.core.ProvisionException: Unknown Host: http://downdload.eclipse.ort/eclipse/updates/4.2/content.xml "]
Thank you in advance!
I don't know if it is possible or not, since seemingly it did not update the older eclipse IDE. If it can be restored the way it was before i run the eclipse.exe, I would be happy.
CodePudding user response：
eclipse.ort is obviously a typo, it should be eclipse.org, I don't know where it is coming from - but its possible you enter it yourself as update site
the runtime error means eclipse cannot resolve all dependencies, which means it could not load bunch of plugins including yours, you need to figure out why on your own, its not possible to debug this remotely, its best to start from the scratch in the new workspace
CodePudding user response：
The solution was easier than expected. The run configuration was modified by the other eclipse version. It was not launched with every plugin. only a selected handful