An attempt was made to disable the spatial index on a geometry column that should not have one. Some geometry columns are designed to only store geometry, not be spatially searched. In these cases, a spatial index is not necessary. The spatial index can add overhead to the dataset, and in some cases, it can even impede the addition of new features. The tool failed because it was not possible for the tool to acquire an exclusive lock on the dataset, which is required to disable a spatial index.
Disconnect all applications that are reading the dataset and remove the spatial index.