Hi Nelson,
The message you are receiving is related to a file being a part file in a distributed file. When a file is added to a distributed file, a location in the header of the file contains a pointer to a location which contains information about the part file such as the partitioning algorithm. I suspect the pointer in file header is no longer valid. I can reproduce a similar error by putting an invalid pointer into that location in the file header. I also notice the size of the file is only 1024. It is possible the file was truncated in some way? It may be the part file pointer in the header is now pointing beyond the end of file.
>LIST NELSON
Invalid Partblock for "NELSON".
Invalid or missing Partblock for "NELSON".
Invalid Partblock for "NELSON".
Invalid or missing Partblock for "NELSON".
Unable to open "NELSON" file.
Hope that helps.
Thanks,
Neil