OneDrive for Business - where do I find a log file?

I'm having problems with MS OneDrive for Business and SharePoint 2013:

I tried to copy a lot of documents at once into my local SharePoint directory, synced with a SharePoint library.

Now, there is a problem with the syncing process and some (most) of those documents are not uploaded to SharePoint. They have a little red rectangle with a white cross on their icon.

I had similar problems when copying forbidden file types (like .exe files) or files with forbidden characters in their name (e. g. "&" and after removing them locally, the sync could proceed.

I did not find any of them, so I'm not sure where the syncing process gets stuck.

Is there a log file for this sync process in SharePoint or in Windows 7 locally where I can see at which point the sync process hangs?

Any help is appreciated

Kind regards

mbbe