As you didn’t provide more info, I would recommend you to:
a. check if your disc drive, or if the DVD disc is damaged and repair the drive/disc if necessary;
b. check if the DVD is from another area, namely if there is [https://www.winxdvd.com/dvd-ripper/dvd-region-code.htm|region code] protection on it; if it is, change the region code of your DVD player
c. try another DVD player like VLC;
d. convert the [https://www.winxdvd.com/resource/dvd-to-digital.htm|DVD to digital] with Handbrake, MakeMKV, WinX DVD Ripper, etc.