Likely Incompatible extensions

You have to check with the legacy system extension's developer. Click the Learn More... button accompanying that message.

Excerpt:

"Legacy system extensions and the apps that rely on them continue to work today. But now is a good time to contact the developer to learn whether an updated version of their software is available or planned. The developer can also explain how to remove or disable the extension, and the consequences of doing so."

Here is a recent Discussion regarding that subject: Legacy system extensions on MacBook Pro computer

As I wrote refer to Legacy system extensions on MacBook Pro computer:

Kurt Lang wrote:

...

These ten are installed by the OS:

ACS6x.kext

ArcMSR.kext

ATTOCelerityFC8.kext

ATTOExpressSASHBA2.kext

ATTOExpressSASRAID2.kext

CalDigitHDProDrv.kext

HighPointIOP.kext

HighPointRR.kext

PromiseSTEX.kext

SoftRAID.kext

Any others you see in the /Library/Extensions/ folder will all be third party.

"Third party" are non-Apple products that you installed. Knowing what you installed on your Mac is your responsibility. For example, I have two non-Apple kernel extensions in addition to those ten. They are for USB to serial devices and their names are not ambiguous because they contain the names of the devices they communicate with. If you examine the Extensions on your Mac perhaps someone else can help you identify what they might be.

Post the contents of your Mac's /Library/Extensions/ folder. Perhaps someone else can help you identify what they might be.