"found character '\t(TAB)' that cannot start any token"

Server log

Caused by: while scanning for the next token
found character '\t(TAB)' that cannot start any token. (Do not use \t(TAB) for indentation)
 in 'reader', line 6, column 1:

What it means

YAML only allows spaces for indentation. The server stops reading plugin.yml at the first Tab and the plugin is not loaded ("Invalid plugin.yml").

What causes it

A line is indented with a Tab. The line number is in the message.

How to fix it

Before

commands:
	home:
		description: Teleports you home

After

commands:
  home:
    description: Teleports you home

Most editors can convert Tabs to spaces for the whole file. Permistry also turns the Tab key into two spaces.

Check the whole file. Paste your plugin.yml or drop the plugin jar into Permistry. It finds this and about 40 other problems, and explains each one in plain words. It runs in your browser and nothing is uploaded.

Open the checker