This record preserves the full-length version of the manuscript that was submitted to SSRN on 2026-02-24. A later revised version of this project has already been posted on Zenodo. However, that later version is more selective and does not include the full set of materials contained in the present manuscript. This upload is therefore retained as an archival full working-paper version. The paper develops Structural Constraint Theory (SCT) as a framework for analyzing why long-horizon systems often fail to sustain effective self-correction. It argues that long-run viability depends on the fidelity of recurrent corrective processes, including error detection, error naming, impact feedback, cost assessment, and meta-correction. The manuscript also includes extended appendices and exploratory formalizations that are not fully preserved in the later shortened version. This version should be understood as a working paper and historical snapshot rather than a final version of record. It may continue to evolve in future versions along the full-length working-paper line. Author: Kelun LiangAffiliation: Independent ResearcherLicense: CC BY-NC-ND 4.0