CA FTB 7275 States my Schedule CA is incorrect for 2017 returns and requesting 15K in taxes. How can I verify?

I got an FTB 7275 through the mail with new computed income and tax liability of around 15K. I filed all my taxes through TurboTax, How can I verify or contest this?

 

Actual Message:

 

"A review of your return indicates that your Schedule CA is incorrect.

 

Schedule CA is used only to report adjustments to federal adjusted gross income(AGI) when that income is taxed differently for state and federal purposes. The difference in taxation must arise from differences between state and federal tax law, not from the source of income.

 

Residents of California are taxed on their income from all sources.

 

We consider you to be a resident of this state during the taxable year and, as such, you are taxable on income from all sources."