Mac App Store receipt is invalid error

This error occurs when the app is automatically trying to update an older Mac App Store version but failing. This error is rare, but some users may be affected.

Mac app store receipt is invalid

To resolve this issue:

PDFpenPro:

1. Quit PDFpenPro

2. Launch Terminal

3. Enter the following:

defaults delete com.smileonmymac.PDFpenPro MASReceipt

If successful, there will be no response.

4. Launch PDFpenPro, and you should be back in business.

PDFpen:

1. Quit PDFpen

2. Launch Terminal

3. Enter the following:

defaults delete com.smileonmymac.PDFpen MASReceipt

If successful, there will be no response.

4. Launch PDFpen, and you should be back in business.