Getting white vignetting in the edge after using DSS

[cleairx]

After stacking in the deep sky stacker I was tweaking details on editing software I got a big white vignetting in the edges. I am not sure why as I did not have any have to vignette when I was taking pictures in the fields, rather I got them after stacking on DSS.

Can someone tell me why and how to prevent it if anyone knows why/how?

I am assuming that it is something to do with my flat frames and the fact that I have a very short exposure time

Total exposure time of the picture I took is 100 seconds (indeed, very short), and I used 15 flat frames 

[michael8554]

So have you solved the problem of "No picture to save" you had in your other DSS post ?

Michael

[cleairx]

On 13/08/2022 at 11:50, michael8554 said:

So have you solved the problem of "No picture to save" you had in your other DSS post ?

Michael

Yes, I am sorry it was me being rude 
It was my first time taking a star pic with a telescope, I was very excited and worried when I faced a problem that I forgot to reply to the previous post. Apologizes to all stargazers who attempted to help me 

[michael8554]

It would seem the Flats aren't correctly correcting the Subs.

Post a jpeg of one of your subs, and of one of your flats.

Michael

[ONIKKINEN]

Did you take darks and bias/darkflat frames? (just bias or darkflat, not both at the same time)

Overcorrection of flats happens when you omit some or all of the above.