From Civilization V Wiki
Below is a list of Frequently Asked Questions and answers
How do I delete a mod?
Mods can be deleted in-game via the mod browser. First, click on the mod to view the mod details. Then select the "Delete" button. A confirmation prompt will appear asking if you are sure you would like to delete your mod. A check box may or may not be there also asking if you would like to delete any user data associated with the mod. After clicking yes, the mod will be removed.
HELP!!! My mod won't work!!
The first thing you should do is navigate to <My Documents>\My Games\Sid Meier's Civilization 5\Logs and open up Database.log, Modding.log, and Lua.log. There are other log files in this folder, but these are the most useful when debugging mods.
Database.log contains important info concerning the game database. In this log you will find any database errors that occurred when activating the mod such as invalid SQL commands, missing references, etc. Most of the time, this log will hold the key to why the mod is not functioning.
In the case of debugging UI's, Lua.log is vital. This gives you every single Lua print statement and Lua error that happens in the game. This log can get VERY BIG.
Modding.log will give you any errors that occurred in the mod info or just generic modding framework errors. These typically happen when creating custom *.modinfo files outside of modbuddy.
We are working towards making the end user and mod creator more aware of potential issues when activating a mod and hope to improve upon this in future updates.
How do I change my language to a custom language?
In the update released on October 22nd, the drop-down for "Written Language" was removed. Changing the written language is still possible but must be done manually. Open <My Documents>\My Games\Sid Meier's Civilization 5\config.ini and modify the "Language" entry. Be sure not to modify other fields such as "SteamLanguage" as that will not do what you expect it to do.
For more information on custom languages see the guide on creating a custom translation here
How do I enable the Tuner?
To enable FireTuner, open "<My Documents>\My Games\Sid Meier's Civilization 5\config.ini" and replace "EnableTuner = 0" with "EnableTuner = 1"
What Paths do I enter in the ModBuddy Update Wizard?
The game path should be the path where Civilization 5 was installed to Typically it is: <Steam Install Path>\steamapps\common\sid meier's civilization v\
The user directory path should be: <My Documents>\My Games\Sid Meier's Civilization 5\
What are the software requirements for the SDK?
Civilization 5 must be installed.