This research is motivated by a breach of contract dispute in a revolving fund financing agreement between the Management Agency for Revolving Funds of Cooperatives and Micro, Small, and Medium Enterprises (LPDB-KUMKM) and the Sumber Abadi Savings and Loan Cooperative. The dispute arose from the cooperative's failure to meet its payment obligations under the agreed financing terms, as examined in Court Decision No. 107/Pdt.G/2021/PN.Mks. This study aims to analyze the legal existence of LPDB-KUMKM’s revolving fund financing regulations and the judges' legal considerations in resolving this breach of contract case. This is a normative legal research employing statutory, case, and conceptual approaches. Legal materials were gathered through a literature review and analyzed qualitatively. The results indicate that LPDB-KUMKM's revolving fund financing possesses a solid legal foundation, and the legal relationship between the parties stems from a valid agreement. However, a breach of contract occurred in practice due to the defendant's default. The panel of judges declared the lawsuit inadmissible (Niet Ontvankelijke Verklaard/NO) because the plaintiff failed to legally prove the issuance of a default notice (somasi) as required by Article 1238 of the Indonesian Civil Code. This study concludes that the judges' considerations leaned heavily on the formal aspects of the lawsuit rather than the substance of the breach of contract, resulting in suboptimal legal protection for LPDB-KUMKM.