If you are getting “Exception from HRESULT: 0x80040E60” error while executing FullTextSqlQuery then most probably it is due to your Order By column. Make sure you use that property in Order By clause which is configured to have a single value in Manage Property configuration screen.
Make sure you have selected “Include values from a single crawled property based on the order specified“ option otherwise; you can not sort results by that property.
The reason behind this restriction is that logically sorting can be performed on objects who have single value which can be compared to other object’s value and then the precedence can be determined. On the other hand, if objects have multiple values then their precedence can not be determined.