Is the document you want to work on locked (marked with a lock)?
Another user is currently working on the document.
The last user to work on the document did not close it correctly. The document will be unlocked when editing is finished properly, but in exceptional circumstances (power or internet connection failure, editor failure...) the unlock instruction will not be sent to SingleCase from your computer.
HOW TO PROCEED:
In the "History of version and Info" section, you can check which colleague is currently working on a document. The colleague's name will appear in the top right corner. Then just ask your colleague.
If the ""History of version and Info" section does not list the name of one of your or colleagues, but only the option to open the document, it means that you are the one who did not properly complete the last operation on the document.
In this case, the solution is to unlock the document (in the same place) with the "Unlock now" command immediately.
Then open the document and make sure it contains the last changes, or that the last edit time matches your last save.