I have registered a datasource but later deleted it as I wanted to make modifications to the relative path. But when I tried to created it next time with most of the attributes same as previous (With only path changes), it is throwing validation error saying the environment (http://nplpeasap.com:8000) already exist and cannot create again. Where can I see those environments? I can perhaps reuse if it allows to create a new datasource.
You can use button “Stop application” to stop the environment and once it is stopped, you can clear it using button “Clear environment”, but the environments are part of the license you purchased. So if you got more environments then you need, you need to take up contact with Mendix and revise your license, if possible.