If you are having trouble updating or registering your plugin, chances are that there might be something wrong with the manifest file. To quickly determine if this is the issue, you can use this validator. Just provide a url to your repository and press submit, shortly after you will know the current status. For quicker debugging of your json code, there is an option of pasting the contents of your manifest file into the textarea below. This come in handy when you would like to make lots of small changes and adapt your content according to the debugging information.
Do you still have problems even if the validator can not find anything wrong? Then you might have wrong setting for you webhook, take a quick look at how to create a plugin to see if the setup is correct. If you still did not find anything, please contact us and we will have a look.