Korg Forums

Here's a thing: if you use FTP to copy files onto your Kronos, be careful with symbol characters in the file names. DISK mode cannot handle certain characters and locks up, forcing you to switch off/on. I found out the hard way; fortunately I had saved my changes first.

Specifically, this happens in DISK mode when you select a folder containing the errant file and tap the on-screen Open button. The button is drawn 'pressed in', but the screen freezes and does not refresh to display the folder contents. All the physical switches become unresponsive, so no chance to leave DISK mode. Only option is to hit the big ol' power switch.

In my case, I had transferred a file called "WDWS[F#]-Perc.wav" from my Windows PC to a folder on the Kronos via FTP . The problem is caused by the square brackets.

Here's a summary of all the symbols you might be able to type on a Windows QWERTY keyboard (mine's a UK one - ymmv):

• 1) Valid in file names in Windows and on the Kronos ___ ! # % & ' ( ) - . @ ^ _ ` { } ~ and space
  2) Risky symbols to use in file names on the Kronos____ $ + , ; = [ ] € £ ¦ ¬ (but valid in Windows!)
  3) Invalid symbols in file names on both platforms _____ " * / : < > ? \ |

You can use the characters in set 1, but avoid set 2 characters. TBH I haven't tried the other characters in set 2, I don't want to keep crashing my Kronos just to prove the point!
(NB: Windows won't allow you to use set 3 characters anyway, so they're not an issue.)

I derived set 1 by inspecting the Kronos on-screen file-naming 'QWERTY keyboard' dialog box (it's a more restricted version of the SET LIST/COMBI/PROG/SEQ-naming dialog box). Using this, there is no chance of entering invalid characters; file names created here are always OK. I assume that any characters not found on that dialog box (hence sets 2 and 3) may cause the freeze.

Obviously, the Kronos can only enforce valid naming within its own UI - it has no control over what you do on other devices! But the FTP process still allows you to copy files named with risky characters.

Be careful out there, people! Practice safe symbols!

Thanks for that Grog96.
Could well be in some sticky section

Thanks for pointing this out

I add that Mac users should be especially aware of the file naming restrictions, because there are only 3 prohibited characters:

/
NULL
:

It is directly related to file system formats.
We all should avoid FAT , NTFS , HFS+ and APFS reserved words.

You shouldn't use those special characters on ANY system. Not on your computer or smartphone or whatsoever.

Windows is one of the few operating systems that uses a backslash for directories. Most other systems and web servers use a simple slash.
And even a simple blank space gets often escaped with %20 which makes hyperlinks very hard to read and type. Moreover you got no control about file ordering. Many systems handle those names differently.

we are not anymore in 1970 : we are in 2020 ! It is hard to believe that all those engineers who work in the software world cannot do nothing concerning these old, very old and special characters. Fifty years already....