Exception thrown Error in visual studio 2019

In using visual studio 2019 I'm getting an error while trying to scanf a string (for example scanf("%s", str);). The error appears specifically to this line of code.

Exception thrown at 0x78D398F1 (ucrtbased.dll) in Project1.exe: 0xC0000005: Access violation writing location 0x00000030.

The code works fine on my second computer. I have tried to erase visual studio completely and reinstalling it, unfortunately with no luck. Thank you in advance for your help.