1) check server compatibility for each step of any script that will be run by a server schedule. And some steps can be either compatible or incompatible based on what options for that step are selected.
See this thread for scripted find examples: Scripted Find Examples
2. Don't use repeated fields for this kind of thing. Repeating fields are what the flat file version of FileMaker used for this purpose many years ago to try to do what we now do with a related table. (Repeating fields became obsolete for most uses with the release of FIleMaker 3.0)