Some file in a liberary can't modify

Hi,

since few days, we have a library with files and we can’t modify them online. Our version is Seafile Pro 7.1.7.
If we open with onlyoffice no change and file still in lock. If we open for example a md file, when we click on save we have an advice who said : impossible to save.

I check in log file but I can’t find the error. Perhaps I don’t look in good file…

Someone can help me ?

Thanks a lot.

Gérald