Invalid filename error?

[Phoenix-D]

Anyone else ever get this? SEIV Gold is cripppled right now for me. I can start a game with any mod fine. However ANY time I hit end turn the error

Invalid Filename.

appears. Then the game screen is shown again but none of the buttons work and I have to close the game.

[Suicide Junkie]

Make sure SE4 can write to the savegame and temp folders.

Make sure you have a temp folder, too.