If they find out your marriage is fraudulent, entered primarily into in order to get immigration benefits.
Many K-1s don't have another interview, but you will need to provide an Affidavit of Support, form I-864, to send in with your AoS package. If you don't make enough money, you will need a co-sponsor. Do not send in your AoS package before you have everything you need, including the Affidavit of Support. Keep in mind there is no time line for you to file. All that matters is that you got married within 90 days of arrival in the U.S. You can now file for AoS at your own pace.
The son of a German mother and a Swedish father, I have lived in 6 European countries before immigrating to Southern California two decades ago. I work as a corporate attorney in Santa Barbara and my main interest lies in issues concerning multiple citizenships.