What If My File Won't Import?

Error Message Reference

Find your error message and jump to the solution:

"Unrecognized file format"

Crescendo checks the actual file content, not just the file extension. This error means the file's internal structure doesn't match any supported format.

Common causes

• Wrong extension—File was renamed with a music extension but isn't actually a music file
• Text file with music data—Some websites serve XML as plain text instead of MusicXML
• HTML download page—You downloaded the webpage, not the actual file
• Unsupported format—Finale (.musx), Sibelius (.sib), MuseScore (.mscz) are not MusicXML

Solutions

1. Check the source—Make sure you downloaded the actual file, not a preview page
2. Export as MusicXML—Open the file in MuseScore (free) and export as MusicXML or compressed MXL
3. Export as MIDI—Most notation software can export MIDI files

"Already in library"

Crescendo uses content-based detection to prevent duplicates. If you import the same piece twice—even with a different filename—it recognizes the duplicate.

What this means

• The file you're importing has identical content to something already in your library
• The error message tells you the title of the existing piece
• Crescendo computes a unique "fingerprint" (SHA256 hash) of each file's content

Solutions

• Check your library—The piece is already there, possibly under a different name
• Use the existing version—Search for the title shown in the error message
• Different arrangement?—If you want a different version, make sure the file content is actually different

"File too large"

Crescendo has size limits to ensure smooth performance on all devices.

Solutions

• Use compressed format—MXL files are typically 90% smaller than uncompressed MusicXML
• Split large works—Import movements separately instead of the entire symphony
• Remove embedded media—Some MusicXML files include embedded audio or images

"MIDI/LilyPond conversion failed"

MIDI and LilyPond files are converted to MusicXML before import. If conversion fails, the file may be corrupted or use unsupported features.

For MIDI files

• Verify the file works elsewhere—Try opening in MuseScore, GarageBand, or a media player
• Re-export from source—If you have the original notation file, export a fresh MIDI
• Try MusicXML instead—Export as MusicXML from your notation software for better results

For LilyPond files

• Check for Scheme code—Custom Scheme functions are not supported
• Remove \include statements—External file references cannot be resolved
• Verify syntax—Make sure the file compiles successfully in LilyPond
• Export as MIDI—Use LilyPond to export MIDI, then import that instead

"Invalid archive" / "Cannot read file"

These errors indicate the file is damaged or incomplete.

Common causes

• Incomplete download—Download was interrupted before finishing
• Corrupted transfer—File was damaged during email or cloud sync
• Encoding issues—File contains invalid characters (should be UTF-8)
• Truncated ZIP—MXL archive is incomplete

Solutions

1. Re-download the file—Get a fresh copy from the original source
2. Check your connection—Use a stable connection for large files
3. Verify the file opens elsewhere—Try opening in MuseScore to confirm it's valid
4. Request a new copy—If someone sent you the file, ask them to send it again

"Potentially malicious file detected"

Crescendo scans files for known attack patterns. This is a security protection, not a bug.

What triggers this

• XML bomb patterns—Files designed to crash software by expanding to huge sizes
• Suspicious compression—Archives with abnormally high compression ratios (zip bombs)
• Deeply nested archives—ZIP files containing ZIP files containing ZIP files...

What to do

• Be cautious—If you downloaded this from an untrusted source, don't try to import it elsewhere
• Get from official source—Download from MuseScore.com, Mutopia, or other trusted sites
• Check file origin—If a friend sent this, ask them to re-export from their notation software

"Could not save file"

The file was validated successfully but couldn't be saved to your device.

Solutions

1. Check available storage—Make sure you have enough free space on your device
2. Restart the app—Close Crescendo completely and reopen it
3. Try again—Temporary issues sometimes resolve themselves
4. Restart your device—If the problem persists, try rebooting

URL Import Errors

When importing from a URL, additional network-related errors can occur:

General Troubleshooting Steps

If your error isn't listed above, try these steps:

1. Verify the file works in another app
   Open the file in MuseScore (free), a media player (for MIDI), or another sheet music app. If it doesn't work there either, the file is corrupted.
2. Re-download or re-export
   Get a fresh copy of the file from its original source.
3. Convert to a different format
   Open in MuseScore and export as compressed MXL (best) or MIDI (alternative).
4. Check your device storage
   Make sure you have at least 100 MB free.
5. Update the app
   Make sure you're running the latest version of Crescendo.