Recovering a NAADSM scenario file after a crash

Occasionally, when a user is entering parameters into NAADSM/PC, an error occurs and the user is unable to save his/her work before the application either crashes or must be shut down. Although we hope these occasions are rare, they do sometimes occur, particularly with beta versions and major new releases of NAADSM.

The best course of action (as with all computer programs) is for users to save their work often. Fortunately, however, if you find yourself in the situation described above, all is not necessarily lost: it is possible to recover at least some of your work. This note describes how you can restore an unsaved NAADSM/PC scenario file in the event of a crash.

When you open a scenario file in NAADSM/PC, the appication will automatically create two temporary files in the same directory as the open scenario file. Changes that you make (e.g., new or altered parameter values) are stored in one of these temporary files until you save your scenario. These temporary files are updated whenever you navigate between scenario parameter wizard screens (see chapter 8 of the NAADSM User's Guide), for example, by using the "Back" or "Next" buttons on these screens.

The two temporary files will have the same file name as one another, but they will have different three-letter file name extensions. These temporary file names will be different each time you open a NAADSM scenario, but they will always begin with three dollar signs ($) and a tilde (~) character, followed by four alphanumeric characters. One will have the three-letter file name extension of "ldb", and the other will have the extension "tmp". (Note: Microsoft Windows will not display the three-letter file name extensions unless you configure it to do so. For more information about displaying file name extensions, please see these pages on Annoyances.org or the Microsoft support website.) The two temporary files will have names that look something like the following. The exact file names will be different, but the patterns will be the same:

• $$$~184F.ldb
• $$$~184F.tmp

The *.ldb file will be small (1 or 2 KB) and can be deleted. The *.tmp file will be substantially larger (on the order of several megabytes or more, depending on the complexity of your scenario). This file contains your scenario and all parameters that you have entered. To recover your data, rename the *.tmp file to something like the following (note that the three-letter file name extension is also changed):

• recovered.mdb

You will then be able to open recovered.mdb in NAADSM/PC, and all parameters that were temporarily stored the last time you switched between parameter wizard screens will be restored.

As always, if you encounter a situation that causes NAADSM to crash, please either post a note (with as much information as you can provide about exactly what you were trying to do and the error message that you saw) to the NAADSM Support Forum or contact us. Feedback from users is critical as we continue to improve NAADSM. Thanks!