To unlock a chapter that has been checked out for editing, you have the following options below, which you can also see the full list of options by clicking on the padlock icon as indicated here.
Save Back to Server
Clicking edit in InDesign or InCopy locks the chapter in CtrlPrint. They remain locked until you use "Save to Server" in InDesign or InCopy. To do this, click on the CtrlPrint -> Save to server, which can be found in the far right of the menu bar. The document will then be saved back to the server on CtrlPrint and unlocked for others to edit.
Open Recent
In instances where the application might close without saving back to server. You can open InDesign or InCopy from your Start menu and click File -> Open Recent to find the file that you were working on and then click "Save to server" with the steps shown above to save it back to server. This will once again unlock the chapter on CtrlPrint for others to edit.
Windows Explorer
If you are not able to open your document through "Open Recent", another way is to find it through Windows Explorer. To do this, click on the padlock icon, which will bring up the option to click "Locked chapter options". Once you click it, you will see the menu of options below
Under Step 3, you'll find the file path. After copying the file path as indicated, press "Win + R" or "Window symbol + R"which will open a prompt in the bottom left corner. You can paste the file path into the prompt using "Ctrl + V" and then click "OK" to bring up the location of the file you were working on. When you have found your file, open the file with the information here and once it is open in InDesign or InCopy, follow step 1 to Save to server.
If you have a mac you can use also do the same by opening "Finder" and clicking "Command + Shift + G" or "⌘ + Shift + G". Then copying the file path as indicated and in the "Go to folder" paste using "⌘ + V", after click"Go" to bring up the location of the file you were working on. If you are working in InCopy then you should find the INDD file and right click to select "Open with". Once it is open in InDesign or InCopy, follow step 1 to Save to server.
Cancel Your Editing
If it is a case where you have not made any changes or don't need to save your work, you have the option to Cancel your editing. You can do this by typing "CANCEL" into the text box and click "Cancel Editing and Unlock", which will unlock the document on CtrlPrint for others to edit. Please note: if you do this, any change you have made will not be saved.
Locked Chapter Options
If you press on the red padlock icon that is visible once a chapter has been locked, it will bring up the button to see all available options if you click the "Locked chapter options".