# TS1243: '…' modifier cannot be used with '…' modifier.

> Two modifiers that can't be combined are on the same declaration, for example `abstract` with `private` or `static`. Remove one.

## What it means

Some modifiers contradict each other. An `abstract` member must be implemented by a
subclass, so it can't be `private` (subclasses can't see it), `static` or `async`, and a
`readonly` member can't be an `accessor`. The message names both modifiers.

## Example

```ts
export abstract class Shape {
  private abstract area(): number;
}
```

## How to fix

- Remove one of the two modifiers. For abstract members, use `protected` instead of `private`.

Source: https://ts-r.dev/errors/TS1243/