I have just finished a comp and was pretty happy with it.
I them started on another comp with the intention of copying the text into my new comps and changing the words.
As I started tracking the new comps I noticed the warning below on my first comp.
Analysis solve failed, though it was working and I was pretty much finished with it.
If the first comp's camera solution is working for you and you have added all 3D elements or place holders you are going to add to the scene then you are through with 3D camera tracking and you should delete the effect. If you analyze footage a second time the camera you created will not change. To use the new analysis you should delete the first camera and all the placed 3D elements you put in the scene .
The solve can fail for many reasons.
I suspect the latter is what happened to you.
Once you have a shot solved and have added your camera and established the origin delete the Camera tracking effect from the footage layer and purge your cache. Then save the project Start a new composition, and close the first one before you start another camera track.