Final answer:
An analytic snapshot might fail due to the running user being inactive, changes to the source report into a matrix format, or issues with an Apex trigger on the target object. Utilizing a custom object or the report's creator not being an administrator should not directly cause a snapshot failure.
Step-by-step explanation:
There could be several reasons why an analytic snapshot might fail during a scheduled run. If the running user becomes inactive, Salesforce cannot execute the snapshot because it is tied to the user's permissions and access. In the instance where the source report has been changed to a matrix report, it might no longer meet the criteria for the snapshot, leading to failure. The type of object being a custom object is not inherently a problem, so that should not cause a failure. Additionally, the presence of an Apex trigger on the target object could introduce complications but not necessarily direct failure unless the trigger has issues like errors or execution limits. Lastly, the fact that the source report was not created by an administrator is irrelevant to the success of an analytic snapshot.