My Units did not attack/capture/spy on the Resource Cache. Why did this happen?

Any Units you send to a Resource Cache will be returned to your Base if any of the following situations occur while they are on their way:

- The Cache disappears from the Map. This occurs if there are no Capture attempts or Attacks on a Cache over a 24 hour period.
- The Cache runs out of Resources, and therefore disappears from the Map.
- The Cache is captured by a member of your Alliance.
- The Cache you were trying to attack or recon on becomes vacant.