91 (E)- Conversion from '%1(%2)' to '%3(%4)' not supported
This error may occur also while copying an instance are collection. When copying a single instance or assigning a value, a conversion error has been detected or the error occurred while copying one of the referenced instances. When copying a collection an incomplete copy error has been indicated for one or more instances of the set.
If the TRACE file variable has been set one may find more detailed information about the error viewing the trace file.