Import into Dorico 4.0 fails when Time Signature X is present in Dorico 3.5 project

Problem: When opening a Dorico 3.5 project containing a “X” time signature (a bar with undefined length), Dorico 4.0 crashes.


  1. in Dorico 3.5: Delete the X time signature(s) (in my project the bar containing 14 beats was replaced by 3 and a half bars of 4/4)
  2. Save the project in Dorico 3.5 with a new name.
  3. Import that project in Dorico 4.0
  4. In Dorico 4.0, go the bars that you changed. Re-instore the X time signatures as they were previously in the 3.5 project.
  5. Solved.

It took me about 10 hours to identify the exact nature of the problem, in a fairly complex project file of about 10 Mb, and about 1150 bars…

In general, such projects certainly don’t crash when opening them in Dorico 4, so I suspect there is something else going on. If you would please do Help > Create Diagnostic Report and upload it here, and provide me with the project file that crashes (you’ll need to email it, since it’s too big to attach here) we’ll look into the problem to determine what’s really going on.

Hello Daniel, I reduced the concerto to 36 bars, keeping the suspect bar with the X time signature.
Dorico 4.0 continues crashing, on the following systems:

  • Win 10 Home, 12-core processor 4.1 GHZ, 32 GB RAM, 1.5 TB SSD, Dorico 4.0 Pro
  • Mac Mini M1, 16 GB RAM, OS 12.1, Dorico 4.0 SE
    I’ll send you the Diagnostics report of the WIn DAW and project file by email.

Hello Daniel,

Please find attached the project file you requested.

Kind greetings, Robrecht


(Attachment Mozart Piano concerto 20 94 - 1 stripped v5 3.5 - Allegro.dorico is missing)

For anybody else who is following along, the problem with Robrecht’s project concerns a bug in some updated code Dorico is using to calculate rhythmic feel. The problem has been identified and fixed and the fix will be included in the forthcoming maintenance update.


Thanks Daniel, I appreciate your quick response (and of your team, thank them from me, please)!
For those looking for a temporary workaround:
Instead of keeping a time signature “X”, replace it by the actual length, for example (as in my project) 2/4 + 83/32. The result is a stable project. :slight_smile: