When designing and deploying a new Theme in SharePoint 3/2007, the metadata for the Theme is stored in the ../12/TEMPLATE/LAYOUTS/1033/SPTHEMES.XML file for the default English sites. Other languages are stored under their respective folders, for example Swedish is using the 1053 folder.

When populating the SPTHEMES.XML file with information about a new Theme, international characters such as ÅÄÖ works fine in the Swedish file but SharePoint fails with the following error message if the same characters are present in the English theme file.

Workaround is to skip international characters in the English file…