ProblemEdit
Mods' content does not appear in game at all.
Cause - Old Version of OblivionEdit
Most new mods are made with the latest version of the Construction Set, which often means that those mod require Oblivion be patched to the latest version (v1.2.0416) in order to work at all.
Solution: Update Oblivion to the latest version.
Cause - UAC ProtectionEdit
Windows 7 and Windows Vista users have User Account Control (UAC) on by default, which prevents applications without administrator privileges from installing and modifying files.
Solution: This issue affects many utilities for Oblivion, so the cleanest, safest method to avoid this and further related issues is to uninstall Oblivion and reinstall Oblivion to a folder outside of UAC protection (i.e., C:\Games). The same applies to Steam, if Oblivion is installed through it.
Solution: If the mod content was being installed through an executable, you can try to give that EXE administrator privileges by right-clicking on it and use the Run as administrator option.
Solution: It is possible to only disabled UAC protection on the folder in which Oblivion is installed. Since Oblivion and other mods modify Documents/My Games, you may need to disable protection on that folder as well.
Solution: Another clean method (albeit a bit less safe) is to turn off User Account Control all together.
Cause - Inactive PluginsEdit
This issue will certainly arise if a mod's plugins are not active in your load order.
- Note: Not all mod's have plugins.
Solution: Make sure the plugin is checked in your mod management utility (i.e., Wrye Bash, OBMM, etc). If you do not use any mod management utilities, use the Oblivion Launcher and go to 'Data Files'. Make sure the plugins are checked there.
Cause - BSA Is Not LoadingEdit
If the mod's files are packed in a BSA, it may be the case that the BSA is not registered or associated with a plugin, and thus this issue will be present.
Solution: See Loading BSAs. In summary: Either register the BSA in the Oblivion.ini or rename the BSA to <some active .esp file (i.e., "DLCShiveringIsles"> - BSA name.bsa).
Cause - BSA TimestampEdit
It is possible that a mod installs loose files which are not being loaded because a BSA with a more recent timestamp than the loose files contains versions of those files.
Solution: Use a file redating tool to set the BSA timestamp to an earlier date than the loose files (i.e., 01/02/2006, one day later than the date of the original BSA files).