Modify Arrow Type in diagram of interaction

[ELETELLIER]

Hello, 
In a diagram of interaction, I try to modify the format of arrow with contents. By default this arrow is in dotted lines, I would like o put it in full line. When I make the modification in the diagram, save and reload it, arrow is again in dotted lines.
Thank you for indicating to me how can it be done?
Cordially.

[nlavigne]

hello, is it possible to describe in details the solution, which element of meta model should i modify ?

[SVanSchoonlandt]

Most likely there is a diagramtypelinkstyle active on this link with condition, this means that when you open the diagram again it's evaluating the condition and applies the corresponding style. If you want to change this behaviour, it requires a metamodel changes.