Sometimes it makes sense for a project to be read-only, and Source Insight allows for that. A project should be read-only if it is used only as a import library, or the project only exists on the project symbol path for auto-completion use. Also, a read-only project can be opened simultaneously by multiple instances of Source Insight.
When Source Insight opens a project in the background to get symbol information for auto-completion or other reference-oriented uses, it opens the project as read-only so that other instances of Source Insight can open the project too.
To make a project always open as read-only, set the read-only file attribute of the project’s .siproj file, which is stored in the project’s data directory.
When you open a read-only project, you will not be able to save any files in the project, or add or remove files from it.