Okay... so I just tried to install The Lost Spires.

First off, I'd just like to say that I had the same problem with Zumbs Lockpicking Mod OBSE: http://www.tesnexus.com/downloads/file.php?id=17894
I fixed that the same way, but didn't expect the problem to return.

The problem is, in short:

1. I've installed a font replacer: http://www.tesnexus.com/downloads/file.php?id=3061
I'm using the font Kingthings Petrock Outline 25 for the dialouge. I really like the change it does. Looks nice I think and I've gotten quite attached to it
It requires (to work) the following line under fonts in the Oblivion.ini: sfontfile_2=Data\Fonts\Kingthings_Petrock_Outline_25.fnt

All that is fine. It has worked fine before. No problems. I've also installed another font for menus and I've had absolutely zero problems before and now related to that.

2. When I installed The Lost Spires (and Zumbs Lockpicking Mod OBSE before as well), a problem suddenly arose. My game crashed every time I started it. Instantly.
It took some time for me to figure out that this was because of the fonts. Exactly why, I have absolutely zero idea. Load order was correct and everything installed correctly.
When I uninstalled the font change mentioned above the game worked again. No crash. Problem is, I didn't want to play Oblivion without the font change. I liked it so much.

3. I found another solution, finally. The connection was apparently that The Lost Spires (and Zumbs Lockpicking Mod OBSE before as well) have BSAs. When unpacking the BSAs and installing the mod again (with all files unpacked normally) the game suddenly doesn't crash. Problem is, unpacking BSAs can make the data files very cluttered.

The mystery about all this is, however:

- Only happens for the font Kingthings Petrock Outline 25 for the dialouge, which works fine otherwise when these mods aren't installed. Works fine with other mods with BSAs. The other font change I have installed works fine as well.
- Uninstalling the above font change apparently stops the crash. No idea how they are related. And why and how this font change and these specific mods are related to each other.
- I've got several mods with BSAs installed. This has only happened so far with "The Lost Spires" and "Zumbs Lockpicking Mod OBSE". I've no idea why it hasn't happened with other mods with BSAs.
- My game isn't heavily modded and it works fine otherwise.

Can somebody solve this mystery? Why is this happening? How are all these things related to each other? So far I've unpacked the BSAs of both "The Lost Spires" and "Zumbs Lockpicking Mod OBSE" and installed the mods that way. Might get troublesome though in the future as the data files folder could get incredibly cluttered.
Help please

Does either mod want or call for a specific font in any of their scripts? Oblivion seems to have issues with more than a set number of fonts. (can't recall the exact number at the moment.)

No neither of the mods need fonts or anything.

The font mod I installed was completely... "independent". It doesn't seem to be a problem of number of fonts. It was just a font "replacement" of the old dialouge fonts. And I installed two font mods. Another one for menus. When I try to uninstall that font mod for menus, nothing changes. It's only happening with that font mod for dialouge.

Strange...

Just wanna be sure, it's safe to install mods that comes with BSAs by unpacking the BSAs? Don't wanna screw up my entire game later just because of some font...

Yes, unpacking the BSA is safe assuming you don't end up changing folder names in the content that's in them.

Your font issue is rather bizarre. I've never heard of something quite that specific and have no idea why Lost Spires would even care.

Alright thanks

I've tried to figure out why as well, but still can't. When I asked Zumbs about it for his mod, he had no idea. His mod doesn't nearly have anything to do with fonts. And no idea why BSAs have anything to do with it either.

Just a quick question. What is so good about BSAs? Is it just good for it looking neat and easy to organize and taking less space (I think), or is there something else that's good about it? Am I missing some major good thing for installing mods with unpacked BSAs?