The problem was caused by a parameter with an expression-generated default value (TimeSpan parameter) having a dependency to another parameter. In this case there was no expression value available and the dialog was not prepared for that. Now, the dialog no longer unexpected close but there is one small glitch: after selecting the value of the dependent parameter, the default value checkbox of the TimeSpan parameter has to be checked. Reworking this would be quite high effort and therefore high risk, so this is not done for now.
The problem was caused by a parameter with an expression-generated default value (TimeSpan parameter) having a dependency to another parameter. In this case there was no expression value available and the dialog was not prepared for that. Now, the dialog no longer unexpected close but there is one small glitch: after selecting the value of the dependent parameter, the default value checkbox of the TimeSpan parameter has to be checked. Reworking this would be quite high effort and therefore high risk, so this is not done for now.