It's most likely a missed error check by the instruction editor. FILELOG editor was missing a few "limit" checks, which SHOULD have been reported as errors when the instruction was edited (e.g. too many entries). We have already fixed a few of these that will be in the next release. I would still like to see the project file, however, or at least that one instruction. Please send it to support@hosteng.com.
Regardless, there is a limit to what a single FILELOG instruction can handle. The work-around is to split it up across 2 (or more) FILELOG instructions with different base file names (e.g. FILELOG w/RunDataA and another FILELOG w/RunDataB).