This file is not a plc file, it is a MDB file, it seems to me that what you might have is part of a project probably GXiec developer.
That type of project comes with a MDB file but contains very little.
Also if you have the whole project & it is GXIEC then you cannot convert it eaisily, the only way is to download it to a plc, upload the code again in GX Dev.
However depending on how it is coded some ladder rungs will not convert.
If you have the whole project (it uses a directory as the filename).
then zip that up & post it, I can open it & if not too large could convert it or at least give you a printout.
All the above assume you have all the files, it's a GX project etc.