Unexpected File Format - SketchUp 2015


The SketchUp model I’ve been working on has the “Unexpected File Format” error… for awhile.
I changed the file from .skp to .skb numerous times and still give me the same error.

Please respond, as this will save me a lot of extra work if this can be fixed…

Note that I have never used any plugin to work on this model.

Try uploading the model here.

Maybe someone else can open it and save it under another name, or version.


The normal file type is skp (SKetchu P) and the skb is the backup (SKetchup Backup) file. Why do you rename the file in this direction?

Changing the name from skp to skb actually worked for awhile, especially when I could not open skb on SU. When the main skp file failed, I could use the other one to access the recently changed, uncorrupted files. Now, the same error occurs regardless.

If I understand, you were manually creating a backup by renaming the skp file to skb?

The problem with that idea is that SketchUp itself creates an skb file each time you open a skp, and if the skp is corrupted this will overwrite your supposed backup. If you want to make a manual backup, make a copy of the skp, don’t just change its extension.

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consider adding in versioning numbers?

MasterFile(v.1). . . MasterFile(v.1—bkpcopy)

easily extended for subsequent re-designs: MasterFile(v1.1). . . MasterFile(v.1.1—bkpcopy)