This is a release candidate

There have been some changes to file loading to speed up startup time, and autosave has been added to edit mode. With those two additions affecting critical features, it is possible that some detail was missed (maybe a particular rare tag in simfiles doesn't work anymore, or maybe files aren't saved or loaded correctly)

Thus, this release candidate build is so that people can test things on non-critical systems to make sure simfiles that worked fine in 5.0.6 also work fine with the changed loader. (non-critical systems just means don't go stick it on an arcade machine where someone might get pissed if a song doesn't load or there's a crash)
If you encounter any problems related to song loading or saving with this build post on the forum or submit an issue with as much info as you have. If it's a particular song that doesn't load right, that simfile will probably be needed to solve the problem.

Next release

If there are no serious bugs in this build, the next release will be in 3 weeks (April 1st), along with any changes that occur between now and then. Work on improving startup time is still ongoing.

Note on loading time

Because this release includes a cache version bump, the first time you load will take much longer than normal because it has to rebuild the song cache. After that, it should be measurably faster. People using SSDs or on modern hardware or with small song collections might not be able to see any difference in loading time.

Now for the notes on the other changes from the last few weeks:

Release notes

This is divided into two sections:

• Player visible changes: New configuration options players should try out,
• Themer visible changes: New (optional) screens that themes can support, new metrics or lua functions, or fixes for existing functions.

Items are roughly grouped into the general part of StepMania they fit into.

Player visible changes:

Edit Mode:

• Autosave:

  The song is automatically saved every 5 minutes if there are any changes.

• EditClearPromptThreshold:

  When clearing an area with the Alter menu, if the area contains at least
  EditClearPromptThreshold notes, you will be prompted. It's a preference
  that is settable in the Advanced Options section or in the Options in Edit
  Mode. Setting it to -1 means it will always prompt, setting it to 1000000
  will make it never prompt.

• Per-chart music:

  Each chart in a simfile can have its own MUSIC tag, pointing to a music file
  to use instead of the normal song music. This does not change the logic for
  when the song ends in gameplay. The time of the last step of any chart is
  still used as the time to end the song in gameplay, so if you use per-chart
  music, make sure your music is the same length.

• Preview tag:

  Simfiles can have a PREVIEW tag which tells Stepmania to use a specific file
  for the preview instead of the song music file. The preview length should
  be read from the preview music file, so cut it right.

Preferences:

• HarshHotLifePenalty:

  Normally, if your life bar is full (1.0), and you get a judgement that would
  decrease it, 0.1 is taken off your life bar even if the penalty would be less
  than 0.1. If HarshHotLifePenalty is false, then the penalty is used instead
  of 0.1.

General:

• DX9 support:

  DX9 support improved, giving a large speed boost and fixing the problem that
  made people get stuck with 16bit color. [xwidghet]

• Mutable actions:

  Pause/Break key now toggles "action" sounds off or on. There is also a
  button in the F3 debug menu for people that don't have a Pause/Break key
  (press A, there are so many that it is off the bottom).

Themer visible changes:

• Bug fixes are marked with [B].
• Functions are marked with [F].

ActorFrame:

• [B] Fixed RemoveChild and RemoveAllChildren Lua functions to delete the
  children instead of leaking memory.

BitmapText:

• [B] Place characters of right-to-left alphabets correctly.
  (untested) [roothorick]

Font:

• [B] Asserts and other things that caused StepMania to crash on font
  mistakes now emit non-fatal errors.

Global:

• [B] foreach_ordered lua function now works on tables that have both number
  and string keys. Number keys are iterated over first.

PaneDisplay:

• [B] Changed to print an error when metrics or player number are omitted instead of
  crashing.

Screen:

• [B] Fixed crash when AddInputCallback is passed nil.

Song:

• [F] GetPreviewMusicPath