ZRS: Universe Not Found Error

I have a customer who recently has started to see the error "“U n​i​v​e​r​s​e​ ​n​o​t​ ​f​o​u​n​d​.​ ​S​e​e​ ​y​o​u​r​ ​B​u​s​i​n​e​s​s​ ​O​b​j​e​c​t​s​ ​a​d​m​i​n​i​s​t​r​a​t​o​r​.​ ​(​E​r​r​o​r​:​ ​W​I​S​ ​0​0​5​0​1​)”" when trying to run and existing report or create a new report. The primary server supporting ZRS has been rebooted to no effect. The one TID on the topic in the Novell Knowledgebase (7009370) notes a problem with insufficient free space on the drive where ZRS is installed; the customer reports 130 GB free on that disk - seems like that should be sufficient.

Notes on solutions discovered by other readers would be most appreciated.