Don't know if you still help with this but, if you still do. Try the following (since this happened to me and I was succesful at it my files were on R12) do a "recover" command on the files. If you are succesful save them once again, and then open the files in R14 (preferably 14.01) and save them again. If you still can't open them then try opening the files in Microstation 95, you'll have to import them into it actually. Good luck.