What the error means
The message usually means the command parser reached a part it cannot read. The cause can be an unsupported command, a missing argument, the wrong edition, a broken selector or an unfinished bracket.
Checklist
- Check whether the command is for Java Edition or Bedrock Edition.
- Check the Minecraft version.
- Make sure the command starts with the correct slash in chat.
- Check selectors such as
@p,@aand@e[type=...]. - Check every quote, bracket and comma.
NBT and components
Many old examples use NBT-style item data. Newer Java Edition item commands may use components instead. If a copied /give command fails, the version difference is often the reason.