Number cannot start with + or .

What it means

JSON numbers may not have a leading plus sign, and a fraction must have at least one digit before the decimal point. These forms are valid in JSON5 only.

Example

{ "ratio": .5 }

{ "ratio": 0.5 }

How to fix it

Drop the leading + and add a 0 before a leading decimal point.

Validate your JSON to see this and every other issue highlighted in one pass.

Diagnostics on this page come from @jsonlint/core, the open-source engine that powers the JSONLint validator. Install it with npm install @jsonlint/core.