OneDrive can work in two different ways, and the default mode will make your uncompressed HMXP Help+Manual project unusable if it is accessed on more than one computer.

The killer default mode: Files in the cloud, only the names shown locally

The default mode is to just show the names of your synchronized files in your OneDrive folders. To save disk space and provide instant access to the current version, the files themselves are kept in the cloud and are read from there when you edit them. If you edit Help+Manual projects in this mode, OneDrive will lock up your files and you will get read-only messages when you try to edit topics.

See How to rescue a read-only project further below for instructions on what to do if this happens to you

The safer mode: "Always keep on this device"

If you right-click on a folder inside your OneDrive directory, you can activate an option called "Always keep on this device". This keeps full copies of all the files in the folder locally. You should ALWAYS activate this for any folders containing Help+Manual projects in OneDrive. It eliminates the locking issues, because OneDrive then doesn't need to perform its complex cloud management operations. Instead, it just uploads and downloads the latest versions of changed files as soon as they are saved locally.

Important: This mode is only safer (not safe!) if it is set on ALL OneDrive copies of the project on all the computers where it is being accessed. If even one version is using the default cloud mode, you can have problems.

The safer mode is just safer, not safe!

It's important to understand that the safer mode is just safer, not safe. If multiple users edit the same project on multiple computers OneDrive will soon get confused about which version of a topic file or project file or TOC file is current. It will then create a "conflicted copy" of the file. Soon you will have a zoo of these copies, each with a different editing status. Good luck cleaning up that mess!

If you are working on your own on multiple computers it's generally OK, since you will never be editing both versions at the same time. But even then you can still get conflicted copies — for example, if you work offline, and then go online while the project is open with unsaved changes on another computer.

If you are a single author using Help+Manual to edit the same projects on multiple computers, you can keep the versions synchronized in OneDrive if you follow these rules:

•Set the "Always keep on this device" option on all copies
Right-click on the project folder in your OneDrive directory and activate the "Always keep on this device" option. Do this on ALL copies on ALL computers where you are editing the project.

•Never leave the project open when you finish editing
Always save and close the project when you're done with editing. Otherwise you risk having unsaved changes that can cause conflicted copies if you return to the project later and then save.

The only way for multiple authors to work on the same project safely in OneDrive would be if a) all authors have the "Always keep on this device" option active on their copy of the project, and b) no two authors ever edit the same project at the same time.

Theoretically, this is possible. In the real world, it isn't. Sooner or later, someone will make a quick edit without checking whether someone else is on the project. Or someone will subscribe to the project quickly in their OneDrive directory, forgetting to set the "Always keep on this device" option, and that will infect the project with cloud locks. Either way, you will have an annoying mess to clean up.

Real-world recommendation: Use multi-user editing (local) proper version control (remote)

The only way for multiple authors to work on the same project safely is to use Help+Manual's own multi-user editing support if you are all on the same network, or proper version control if any users need to access the project remotely. See here for details:

Help+Manual's native Multi-user editing

Version control with Git (recommended) or SubVersion

What happens when you edit a project in OneDrive in its default mode

If you edit an uncompressed Help+Manual HMXP project in a OneDrive folder in its default mode, all the project files are kept in the cloud and only their names are shown in the local folder. As soon as Help+Manual starts accessing the files, OneDrive starts putting its "cloud locks" on the files and you will get read-only warnings when you try to edit and save topics.

When this happens, the locks are permanent and cannot be removed, not even in Windows File Explorer. They are only accessible for Microsoft tools like Office, which use the Microsoft-only Co-Authoring API. If you try to copy or move the project to another location you will still get the read-only messages, because the cloud locks are still attached to the files.

How to make your project editable again

Don't try to copy or move the project! This won't remove the OneDrive cloud locks.

1.Select Save As... in the File menu.

2.Save the project outside of the OneDrive directory, in a local folder where you have full read and write permissions.

3.Delete the entire OneDrive project folder on all computers where it was being used.

4.If you are going to continue using OneDrive (see above), copy the clean project folder into the OneDrive directory and set the "Always keep on this device" option for the folder. Repeat on all computers where the project is going to be accessed in OneDrive.