Sure, here are some common Spotify playlist problems and their solutions:

1. **Problem: Playlist Disappeared**
Solution: Check the "Hidden" section in your Spotify settings. If it's not there, it's possible that you may have accidentally deleted it. Unfortunately, once deleted, it cannot be recovered.

2. **Problem: Can't Add More Songs to a Playlist**
Solution: Spotify allows up to 10,000 songs in a single playlist. If you've reached the limit, you'll need to remove some songs before adding new ones.

3. **Problem: Songs Won't Play or Keep Skipping**
Solution: This can be due to a poor internet connection. Try switching to a different network, or download the songs for offline listening. If the problem persists, try reinstalling the Spotify app.

4. **Problem: Can't Share a Playlist**
Solution: Make sure your playlist isn't set to private. You can change this by going to the playlist's settings and switching the toggle off for "Secret."

5. **Problem: Playlist Won't Sync Across Devices**
Solution: Make sure you're logged into the same Spotify account on all devices. If you are, try logging out and back in again.

6. **Problem: Duplicate Songs in a Playlist**
Solution: You can manually search and remove duplicate songs. Alternatively, use the "Remove duplicates" option if you're using Spotify on a computer.

Remember, if you're experiencing persistent issues, it's always a good idea to reach out to Spotify's customer support for further assistance.