My .jpegs won't open because they have an iCloud extension

Hi, 

I have the same issue.

I move my Mac's Desktop including all files to Dropbox via Drag'n'Drop and most of my .jpg are now shown as .jpg.icloud files. I cannot open them with any program. In "Get Info" I cannot change the program from Preview to something else to open it

as this field is shown as grey. Yet the file sizes indicate that these are not empty inoperable files but still they still contain their data ( e.g 1.6 MB size). I tried changing file extension to .doc / . rtf / .txt but none of them make the files readable. The icon that is shown in Finder says Green on Black: EXEC . Though, in "Get Info" the files are simply stated as .jpg (I do not see .icloud in this interface).

I have tried opening the files in iCloud but they are in the same broken state.

In a particularly bright moment I deleted the original files (GENIUS.....) as I thought all files would have been transferred to Dropbox already.

What I have gathered so far in all kinds of threads is that it could be something went wrong during upload and the system created a placeholder file but eventually did not complete the upload. What would go against this theory is that there still seems to be data within the files as "Get Info" says filesize e.g 1.6 MB.

Can anyone help me with resolving this issue? Are there file converter programs or any last resources?

Thank you very much in advance guys!