While working on a model, sometimes the context menu (the menu that pops up after a right-click) does not appear, and you may have to exit the software to resolve it.
Solution
This can happen due to use of multiple graphics cards or having a modified right click menu.
To resolve it you should not exit from the software, but instead click on any element present in the file - even a line would suffice. By doing this, the software will associate the element's data and process its graphics.
After this, if you right-click, you should find the complete pop-up list as shown below: