PHP error on line 179

Hi,

When I insert that line on my page :
[gravitywp_count formid=”9″ number_field=”27″ decimals=”0″ dec_point=”.” thousands_sep=”,” ]

I got this error :
Warning: A non-numeric value encountered in /home/o2/public_html/wp-content/plugins/gravitywp-count/gravitywp-count.php on line 179

The plugin show the right number but I got that error and I don’t know because it’s working fine.

Thanks for your help.