Increase the heap memory size to >1024 MB
Try running the below command from the command prompt with verbose option set.
java -Xmx1536M -jar AEM_6.4_Quickstart.jar -v
Hope this helps.
So, I was having the same issue and the problem was solved after I uninstalled all JDKs(versions 11 & 14) and left only JDK version 8.
This really worked for me, Thank you