Numbers error "numbers couldn't read the file"
Guys, please help!
I have a very important Numbers file and now I can't open it. The following error message apears: "file can't be opened right now. Numbers couldn't read the file. You can try to restoring to a previuos version."
When I try to browse older versions of the file within numbers app and try to restore any older version, I get another error message: "the document could not be reverted. The file format is invalid. This document can no longer be used because its file become unreadable, so it must be closed."
I store this numbers file on icloud and use it on both my iphone and mac. Before the problems started, when I opned a file on mac numbers, the dialog box apeared promting to choose between two conflicting versions - one on iphone, and one on mac. I chose the newer one (I think it was edited on iphone). After doing that the file got corrupted and above error messages apeared. It can not be opened on ios numbers app or on the icloud.com.
Tried the following with no success:
1) to boot in safe mode and open the file or browse for previuos versions
2) restart mac, reinstall numbers app
3) download or export file form icloud
4) delete numbers cashe file in ~/Library/Caches as suggested on some related posts
Can anyone, please help?
I use latest soft Mojave 10.14.6 and numbers latest version.
Kestas