Q: I attached a couple of images and pdf-files as raster in my model. I worked off line so I used a USB-memory. Later on, I moved all the files to my computer and the rasters are now red in the raster manager list. How can I reload them ?

A: You have a couple of options here.

The first thing Microstation does when you open a design file while there are some raster attached, it goes read into the same path as the design file. If the rasters are there, Microstation will find them. Even if the folder moved from drive F: to drive G: for example. 

This is the easiest\simplest way to do not have raster red highlighted in the dialog. To have design and raster files in the same folder.

Another thing you can do is to manually change the raster's path. To do so, right-click on your raster and select File Name... Select the new path and click OK. But if you have several rasters, it can become quickly annoying.

Finally, you can set the configuration variable MS_RFDIR. Simply add the desire "Expansion" (value) - where you raster is stored. Notice that you can define several path where Microstation will search.