Indesign cannot open file

[lindsey305939368bpi]

Hello

I used the Indesign trial to see what it was like for a project. I liked it so purchased the month subscription. But now when I open my project is says "Cannot open the file. Adobe Indesign may not support the file format, a plug in that supports the fil may be missing. or the file may be open in an another app." 

I don't have it open in another app and now I've lost loads of work and have to start again. Can anyone help?

Thanks

[Peter Spier]

Typically this error is caused either by a lock file (.idlk) that was not automatically deleted from the folder containing the document (due to improper close) or you are trying to open a file from Finder or File Explorer by double-clicking and are not showing file extensions, so have chosen something other than .indd, .idml or .indt file for opening.

[Steve Werner · Accepted solution]

The extension you show in the error message is ".indd.icloud".

That is not a proper extension for an InDesign file. The proper extension is simply ".indd"

[Peter Spier]

Good catch. I didn't read the error dialog. 😞

.icloud files are, I believe, backup synch files and need to be copied back to the local drive to convert. Is that right?