The objective of this contract is to extend and optimize UOP`s single-stage, slurry-catalyzed co-processing scheme. The current task is to complete a long-term operability run using a 0.05 wt-% Mo-based catalyst at approximately 460{degrees}C. The objectives of this run are to demonstrate that high-severity conditions can be run for an extended period of time (at least one month) and to collect enough product sample to do a complete Hempel fractionation and detailed characterization of the individual naphtha, distillate, and VGO cuts. This information will be used to reevaluate the engineering design and product upgrading scheme that was developed under the first co-processing contract (DE-AC22-84PC70002). During the current two quarters, the long-term operability study was unsuccessfully attempted several times. This report discusses these attempts.