Stepmania 5 beta 3 problem

So I just installed Stepmania 5 beta 3 yesterday. Tried running it and it crashed.

This is what the crash info looks like:

StepMania v5.0 beta 3 crash report (build 8, 20140224 @ 15:23:46 Central Standard Time)
--------------------------------------

Crash reason: Assertion 'v.size() > 0' failed

Thread: Main thread
RageFileDriverDirectHelpers.cpp:227 C:/Users/tcorrie/AppData/Roaming/StepMania 5/Themes/_fallback/Scripts/*
IniFile.cpp:21 Reading 'Themes/_fallback/ThemeInfo.ini'
RageFileDriverDirectHelpers.cpp:227 C:/Games/StepMania 5/Themes/DDR SuperNOVA BT2/Scripts/*
RageFileDriverDirectHelpers.cpp:227 C:/Users/tcorrie/AppData/Roaming/StepMania 5/Themes/DDR SuperNOVA BT2/Scripts/*
CommonMetrics.cpp:41 Assertion 'v.size() > 0' failed

005aef1f: void CrashHandler::ForceCrash(char const *) [00400000+1aef00+1f]
0058f50c: void sm_crash(char const *) [00400000+18f4f0+1c]
004cace7: void ThemeMetricDifficultiesToShow::Read(void) [00400000+cab40+1a7]
00673d55: void RageMutex::Unlock(void) [00400000+273d40+15]
0070b960: void ThemeManager::SwitchThemeAndLanguage(class StdString::CStdStr<char> const &,class StdString::CStdStr<char> const &,bool,bool) [00400000+30b680+2e0]
6dfb6403: MSVCP90!std::basic_string<char,std::char_traits<char>,std::allocator<char> >::assign [6dfb0000+63c3+40]
00590802: void StepMania::ChangeCurrentGame(struct Game const *) [00400000+190550+2b2]
00590826: void StepMania::ChangeCurrentGame(struct Game const *) [00400000+190550+2d6]
75803c1b: MSVCR90!free [757a0000+63b4e+cd]
75803c3a: MSVCR90!free [757a0000+63b4e+ec]
75803c3a: MSVCR90!free [757a0000+63b4e+ec]
006e2935: bool NoteSkinManager::DoNoteSkinsExistForGame(struct Game const *) [00400000+2e28c0+75]
00590c69: void SwitchToLastPlayedGame(void) [00400000+190b90+d9]
00593033: main() [00400000+1927f0+843]
757c2e2b: MSVCR90!unlock [757a0000+22e16+15]
75806430: MSVCR90!realloc [757a0000+66415+1b]
758067ab: MSVCR90!realloc [757a0000+66415+396]
757c36c5: MSVCR90!_set_flsgetvalue [757a0000+236b6+f]
757c38b3: MSVCR90!initptd [757a0000+23753+160]
005ae4d4: int GetWin32CmdLine(char * * &) [00400000+1ae420+b4]
005ae255: WinMain@16() [00400000+1ae240+15]
0079678f: __tmainCRTStartup() [00400000+39664f+140]
77ed98c4: ntdll!RtlInitializeExceptionChain [77e90000+4986a+5a]

Static log:
StepMania v5.0 beta 3
Compiled 20140224 @ 15:23:46 Central Standard Time (build 8)
Log starting 2014-10-06 12:58:02
Loading window: win32
Windows 6.2 (unknown NT-based) build 9200 []
Memory: 4095mb total, 4095mb swap (4095mb swap avail)
Video driver: Intel(R) HD Graphics 4000 [Intel Corporation]
10.18.10.3345, 10-28-2013 [pci\ven_8086&dev_0166&subsys_fb201179]
Drive: "TOSHIBA MQ01ABD075 AX0A" Driver: iaStorA DMA: N/A
Drive: "TSSTcorpCDDVDW SN-208AB TO04" Driver: iaStorA DMA: N/A
Sound device 0: Speakers (Realtek High Definiti, 6.3, MID 1, PID 100
Language: en
Theme: DDR SuperNOVA BT2

Partial log:
00:00.333: Loading "/Themes/_fallback/Scripts/02 ThemePrefs.lua" ...
00:00.333: Loading "/Themes/_fallback/Scripts/02 ThemePrefsRows.lua" ...
00:00.335: Loading "/Themes/_fallback/Scripts/02 Utilities.lua" ...
00:00.337: Loading "/Themes/_fallback/Scripts/03 CustomSpeedMods.lua" ...
00:00.337: Loading "/Themes/_fallback/Scripts/03 Gameplay.lua" ...
00:00.338: Loading "/Themes/_fallback/Scripts/03 GamePreferences.lua" ...
00:00.340: Loading "/Themes/_fallback/Scripts/03 ThemeAndGamePrefs.lua" ...
00:00.340: Loading "/Themes/_fallback/Scripts/03 ThemeLibrary.lua" ...
00:00.340: Loading "/Themes/_fallback/Scripts/03 UserPreferences2.lua" ...
00:00.342: Reading 'Themes/_fallback/ThemeInfo.ini' failed: No such file or directory

-- End of report

Anyone know what to do?

"Theme: DDR SuperNOVA BT2"
wondering if that theme is for StepMania 5 or not... if I had to guess, it probably isn't.

That specific assert is from the Common::DifficultiesToShow metric being empty.
This is a problem to report back to the theme author. If the theme wasn't made for SM5 and the author isn't around to update it, you're going to have to use a different theme.
(also, beta 4 was released a couple days ago, see the thread in the Releases forum, still waiting for the Downloads page to be updated.)

UPDATE: I upgraded to Stepmania 5.0 beta 4.

Correct, Supernova BT2 is NOT compatable with Step 5.

However, I cannot get rid of it no matter how hard I try.

I will keep trying things and see if they work

Hm, exactly what did you do when you installed the theme? What have you tried so far when trying to get rid of it?

I installed it a while ago for Stepmania 3.9. It's trying to open that theme whenever I open Stepmania.
I tried deleting it and moving it somewhere else but nothing doing.

Open up %APPDATA%/StepMania 5.0/Save/Preferences.ini in a text editor like notepad.
Look for the "Theme=" lines. Change the theme to "default", so it looks like this: "Theme=default". There will be a general line, and one for each game mode, so make sure you change them all.
See if that works.

My computer does not have %APPDATA%/StepMania 5.0/Save/Preferences.ini. It doesn't even have %APPDATA%.