It is extremely easy to replicate it - at least on my systems (Mac, Ubuntu, both latest update).
1.Create or load the mosaic *esl
2. Reload the same file and rename them
3. Try to save the sequence, you enter the desired name and location and application crashes.
The only think that I can see, is that the altitude values remain the same, something that is clearly wrong. The target will not have the same altitude at 23:14 and 23:31