Eclipse not automatically switching run configurations

Question

Everything was working fine yesterday. I start to work on my project today and Eclipse gives me a bunch of problems. First, it wouldn't let me debug saying "Cannot connect to vm". I don't exactly remember how I fixed that problem, but I did. I was able to debug once again. I just recently created a new project to test something separate from my main project and now Eclipse is giving me some more problems. This time it is saying "An internal error occurred during: "Launching New_configuration". Path for project must have only one segment."

After some searching, I found that it is related to the debug configurations. In order to debug a project now I have to go to Run->Run Configurations and select the project I want to debug. Before, it would automatically do this for me. I would just select a java file from a project and it would debug the project that contained the file. Also, I can't find my new project in the list of Android Applications under Run->Run Configurations. I've tried creating a new one in the menu, but when specifying a source it can't find my project folder even though it is clearly open in Eclipse. Eclipse has been giving me massive headaches lately and I don't understand what could have caused this to happen. Eclipse was left open all night and the computer doesn't go into sleep mode (sorry for wasting power!).

Any ideas on how to get it to see my project and make it automatically debug the right project?

Answer 1

What is the usual case (detailed below as a Run or Debug configuration with no project name) wasn't the root cause:

In the comments, I suggested:

Did you try to import this existing project in a brand new workspace? (to see if this isn't related to some kind of workspace metadata corruption?)

To which the OP Atlos replied:

creating a new workspace seemed to have fixed it. Not sure what could have happened to my old workspace to cause a problem like this.
Should I ditch my old workspace and just import stuff into the new one?

It happens, and can be caused by some process blocking the update of metadata, rendering parts of the workspace unsound.
It is perfectly OK in that case to save/move that old workspace (for reference just in case) and to create a brand new one.

---

This blog post mentions:

It seems that this rather cryptic message means nothing more in my case than “please enter a name and project for your run configuration”.
I did have a “name”, but left the “Project” field empty. Entering a value in the ‘project’ (the “AndroBlip” you see next to ‘browse’) fixed it.
Sources seem to indicate that the same error is produced if you don’t enter a value in the ‘name’-field.

It actually references the similar SO question "Android: “Path for project must have only one segment”".

Note that you would see the same error for trying to have a project within another project (as detailed in this thread).