Increment your hash without characters that directory names don't like.

incHash.js

const incHash = (str) => {
  const singles = str.split('');
  let incNext = false;
  let extendIt = false;
  for(let i = singles.length - 1; i > -1; i --){
    if(incNext || i == singles.length - 1){
      incNext = false;
      let ascii = singles[i].charCodeAt(0);
      if(ascii == 57){
        ascii = 65;
      }else if(ascii == 90){
        ascii = 97;
      }else if(ascii == 122){
        ascii = 48;
        incNext = true;
      }else{
        ascii++;
      }
      if(i == 0 && incNext){
        extendIt = true;
      }
      singles[i] = String.fromCharCode(ascii);
    }
  }
  let newStr = singles.join('');
  if(extendIt == true){
    newStr = '0' + newStr;
  }
  return newStr;
};