When creating a new project in eclipse and you select Create project at existing location (from existing source), you might get
Cannot create project content in workspace
all the time.
You can try to solve this by creating the project somewhere else and dragging the content into that new directory.
But what causes this error is that you put your projects’ source(s) in the directory where your workspace is located.
The recommended approach to avoid this error: name your workspaces something like “Projects” and/or “Accounts”. Not a full path name. This way they get created in your eclipse folder and contain only the .metadata directory.
After that, just place your source(s) somewhere else and add/create them like you intended to do in your preferred workspace.
As a summary: a workspace should just be a name (to which eclipse links some configuration information). Not a physical location (path).