Hi,

can you please post (or PM) first 10 bytes of your file (in hex)?
It's the best to start with the header (it doesn't disclose any sensitive data - chunk is too small).

Use following tool. Mycelium apparently has some issues with restoring old backups.

https://github.com/mycelium-com/wallet-android/blob/master/backuputil/src/main/java/com/mrd/bitlib/BackupUtil.java

This allows you to produce a WIF key, which should be usable in new mycelium.

Let me know over PM, if you'll need help to run it.

EDIT: Attached a guide

Go to backuputil/bin directory and execute
like

This will show you "Private key (Wallet Import Format)".
Send it to your mobile phone (using chat or whatever)
Copy it into clipboard
Open Mycelium > Accounts > Key+ icon > Advanced > Import (this should allow you import from clipboard)

1) Pre-built version (I built it straight from mycelium repo like 30 minutes ago)
Here you can download ready-to-use backuputil.

2) However if you don't trust these binaries (which I totally respect), here is a guide how to compile your own.

• Download and install Android Studio
• In the 2nd step of welcome wizard choose "Custom"
• Check "NDK" in the next step and let the installation finish
• Dowload zipped backuputil source code (green button on the top)
• Unzip it and using command line go to backuputil from the zip file above
• Type "gradle build" into command line
• Go to newly created folder build/distributions
• Unzip backuputil.zip