Many fans are unhappy that this will be the last season of CBS' "Mike & Molly." Among those disappointed is star Melissa McCarthy who posted a tweet Monday afternoon about how "shocked" she was at the network's decision to cancel the show.

The sitcom first premiered in 2010 and will conclude this spring following Season 6. Actor Billy Gardell also took to Twitter to announce it would be the last season of "Mike & Molly" when he tweeted out the premiere date and how many new episodes would be airing.

It remains unclear why CBS decided to cancel the show, but Rondi Reed, who plays Peggy, posted on Facebook saying the network had its "reasons." She also revealed that the show was shopped around to other networks, but they were unable to find a new home.

In addition to starring on "Mike & Molly, "McCarthy has been very busy in Hollywood.  The 45-year-old actress has been filming three new movies, "Cook-Off!" "The Boss" and "Ghostbusters," which are expected to be released in 2016. There is also a possibility she could appear in the Netflix revival of "Gilmore Girls" now that her schedule has just opened up.

"Mike & Molly" is about a couple who met at a Chicago Overeaters Anonymous group who went on to fall in love with one another. The show has won two Emmy awards, including Outstanding Cinematography for a Multi-Camera Series and Outstanding Lead Actress in a Comedy Series, which McCarthy took home in 2011. 

According to Business Insider, CBS may have decided to cancel the show following an 11 percent reduction in the 18- to 49-year-old audience in season five. The comedy held an audience of 8.4 million people, but it's possible McCarthy's salary may have also contributed to CBS pulling the plug.

"Mike & Molly" Season 6 premieres on CBS on Jan. 6, 2016 at 8:30 p.m. EST