plug in error

I am unable to search for plugins. I was updating a bunch of sites and adding sitemap plugins. Then, all of a sudden, it would no longer search for the plug ins and giving me this error in the popular tags box: Warning: number_format() expects parameter 1 to be double, string given in home/content/20/9183320/html/accountantfranklintncom/wp-includes/functions.php on line 155

I can put the plugins directly into the site serverside, but I am updating hundreds of sites and it takes longer to add them to the server.

Any ideas?