First its a problem in mySQL, see the specific database definitions I included in the btnHelp.
The field opmerk is not filled (ie. value = null) and filtering this field is also not filled.
Sorting this field descending gives the error
As workaround, I emptied this field, but as far I know (I don't have access to the application now) I've disabled this (see the application: "Retrieve Results")
I tested is with the Studio version 1.0.40 and Server version 1.0.37
Next week I can test if there are also some errorlog generated in tomcat-logifles
For best results, use the Firefox browser..