Why do my drawing extraction files have a .all extension on them instead of .dgn?
The configuration variable for changing the drawing extraction extension is TF_DRAWINGS_EXTENSION.When the option in Drawing Extraction Manager is selected to "Output to Single Model " it would merge all of the drawing extraction files, .d, .s, .f, .r, into one file. This file would have the extension as noted in the configuration variable, which could be .all or .dgn or whatever you prefer. By naming the extension to .all, it refers to merging in the section, front and rear extractions into one file. if you selected "Output to Multiple Models", your drawing extraction files .s, .f, .r are referenced into a .d file as the master drawing extraction file.
If you have files ending with .all, the configuration variable must have been set to "all" at the time of the calculation in drawing extraction. If you rename any files with .all extension to .dgn, then the link between the model and drawing extraction file would be broken. You will get a message that DEM cannot find the file. The model would need to be recalculated with a .dgn file extension in the configuration variable,TF_DRAWINGS_EXTENSION..