When using Win XP in your native language, the path to the material library may contain unsupportet characters, at least that´s the case on a Danish Win XP / Revit 2011 installation:
C: \ Programmer \ Fælles filer \ Autodesk Shared \ Materials2011 \ assetlibrary_base.fbm
The solution:
Copy the folder C: \ Programmer \ Fælles filer \ Autodesk Shared \ Materials2011"
to a new folder without the use of the unsupported charachter C: \ Programmer \ Shared Files \ Autodesk Shared \ Materials2011
Change the following in the RegEdit:
32bit HKEY_LOCAL_MACHINE \ SOFTWARE \ Autodesk \ ADSKAssetLibrary \ 2011 - LibraryPaths
64bit HKEY_LOCAL_MACHINE \ SOFTWARE \ Wow6432Node \ Autodesk \ ADSKAssetLibrary \ 2011 - LibraryPaths
So it points to the new folder: C: \ Programmer \ Shared Files \ Autodesk Shared \ Materials2011 \ assetlibrary_base.fbm
Credit for this solution goes to Fragel
C: \ Programmer \ Fælles filer \ Autodesk Shared \ Materials2011 \ assetlibrary_base.fbm
The solution:
Copy the folder C: \ Programmer \ Fælles filer \ Autodesk Shared \ Materials2011"
to a new folder without the use of the unsupported charachter C: \ Programmer \ Shared Files \ Autodesk Shared \ Materials2011
Change the following in the RegEdit:
32bit HKEY_LOCAL_MACHINE \ SOFTWARE \ Autodesk \ ADSKAssetLibrary \ 2011 - LibraryPaths
64bit HKEY_LOCAL_MACHINE \ SOFTWARE \ Wow6432Node \ Autodesk \ ADSKAssetLibrary \ 2011 - LibraryPaths
So it points to the new folder: C: \ Programmer \ Shared Files \ Autodesk Shared \ Materials2011 \ assetlibrary_base.fbm
Credit for this solution goes to Fragel