Creating report error

I am running InvoicePlane 1.5.4 on PHP 7.1. When trying to generate a report for the last quarter I receive the following error.


A PHP Error was encountered

Severity: Notice

Message: A non well formed numeric value encountered

Filename: src/Tag.php

Line Number: 2723

Generating a Report by customer “/reports/sales_by_client” does work as it should.