I created a model using the ModelBuilder which requires three inputs: database, output coordinate system, TDM Network Source File (input shapefile). They show up as blank parameters in the model dialogue window, so any user of this model can select the path/file on their local computer when using this model tool. The final outputs are two feature classes in the database, they're also shown as model parameters because they will be inputs for other models later (nesting).
The problem is that if I enter the inputs in the model dialogue window, the model fails to run and returns "ERROR 999999: Error executing function. The table name is invalid. Failed to execute (Merge)." At this step, the model tries to merge two point event layers into one feature class saving in the database. However, if I enter the inputs in the model editor window, the model runs perfectly without the error message.
I did notice that the Output Dataset name in the Merge function automatically changes from "%Database%\TDM_Merge_Points" to "%Database%\TDM_Merge_Points.shp" if the values/paths of the inputs in the model are left blank. I can only delete the ".shp" in the Output Dataset name when I entered the inputs in the edit window instead of the model dialogue window. I can't figure out what's the different between running the model from the model dialogue window and edit window besides this minor difference of Output Dataset name.