The current version of microstation ie V8i doesn't quite work like it used to in the old days where it was dynamic write to the server/ hdrive… nowdays it uses in lay terms some sort of cache and timing and  checks if the file has change a lot then writes to the server now there can be a fair lag time over a network server so this I think is supposed to help compensate that… but if it crashes you can still loose data and it doesnt seem to let the server know you want the file to stay open.. I think this would be a bad thing to leave the file open if its crashed.. so thats why your colleague opened it without the warning..

First if this file always crashed you will need to make a new version just open a new drg and ref attach the bad file via ref manager turn of nesting for now select everything in the visible plane and copy into the active now turn on nesting and set copy references then detach the bad file.. you should now have a  pretty good clean version to replace the bad file with..

There is only a couple of things that can be done to prevent this happening to you again

Axiom file fixer will repair the corruption that may have caused your file to crash..but its a bit expensive… especially if its not dgn corruption that causing the problem..

But it maybe that your upf file itself is either too big or corrupt.. delete it and rebuild your prefs.. make a backup copy when your finished so you don't have to rebuild it again… ask your cad manager or IT if there is a backup default user one  you could reuse…

Get a checking out system or program that automates making a copy and  puts a copy on your hard drive or working folder from the network for you to edit but makes the original write protected to read only so even if yours crashed it doesnt wreck the network read only version ..Projectwise does this unbelievably well but its expensive too..

search the web for checking out or cad file management tools.. there are loads of them ..

Personally I prefer a user based system work flow approach…

The current folder has a read only with rev number at the end of the file name.. you want to update a drawing then you must copy this out to the working folder and  change the rev name number

ie in the current folder is mydrawing_REV A.dgn.. it is write protected read only..

There is a sub folder there for superseded for all previous revs to live in..

so you want to update mydrawing_REV A.dgn   to REV B so copy and  rename to mydrawingREVB.dgn to the Working folder you can now edit it to your hearts content and  nobody else is going to use it… when  you finished move it back to its original location  then unwrite protect the previous version … and  merge all your ref files so it becomes static or frozen in time as it was before edits.. then move it to the superseded.. server space is cheaper than losing drawing data… this then also need a database or excel file for you to keep track of revisions and  by who, when etc .. a bit of a pain but it becomes your drg register and  helps find drgs and  gives some confidence on the revision process.. your QA guys will get very excited if you tell them about this…