To be trying to unlock a safe, you will be worried over the failure of your plans not reaching quick maturity.
To find a safe empty, denotes trouble.... Ten Thousand Dream Interpretation
2. If putting possession in safe, indicates that this is the way one is treating one’s life.
3. If locked up, the dreamer may feel trapped.
4. One has achieved a goal by hard work and/or daring.
5. A place where one hides secrets. ... New American Dream Dictionary