Diagnostic codes: pattern-invalid: A pattern has an empty folder name, a `**` that is not a whole folder name, a capture without a name, or the same capture name twice. # pattern-invalid > A pattern has an empty folder name, a `**` that is not a whole folder name, a capture without a name, or the same capture name twice. Config problems. This text is what `archangel docs pattern-invalid` prints. A pattern has an empty folder name, a `**` that is not a whole folder name, a capture without a name, or the same capture name twice. ## Example ```json { "elements": { "ui": "src/ui**/x" } } ``` ## What to do Write `**` as a whole folder name (`src/**/x`), give each capture a name of letters, digits and underscores, and use each name once.