MS Project : Can't use Resource Pool

It seems that you are experiencing an issue with using the Resource Pool in Microsoft Project. The greyed-out option for "Use Resources" when trying to share resources can occur for several reasons. One common reason is that the resource pool and the task file must be compatible and properly configured.

Here are a few things to check:

1. File Compatibility: Ensure that both the resource pool and the task file are saved in a compatible format. They should both be .mpp files.
2. Resource Pool Setup: Make sure that the resource pool is correctly set up and that resources are properly defined within it.
3. Open Files: Confirm that both files are open in the same instance of Microsoft Project. Sometimes, having them open in separate instances can cause issues.
4. Permissions: Check if there are any permission issues that might prevent you from accessing the resource pool.
5. Version: While you mentioned the version of your Project Online Desktop Client, ensure that it is fully updated, as certain features may not work correctly in older or incomplete versions.

If you have checked all these aspects and the problem persists, it may be helpful to consult the official documentation or support resources for further assistance.

References:

• Error occurs when you add or edit a Resource in Enterprise Resource Pool
• Project architecture overview

Dear @Jim Lee,

Thank you for posting your question in the Microsoft Q&A forum.

The “Use Resources…” option is greyed out because your Project Online Desktop Client is currently connected to Project Web App (PWA) with Enterprise features enabled. In this mode, the application expects resources to come from the Enterprise Resource Pool, not from a local .mpp resource pool file.

__Note: __If you use Project Professional and resources exist in your organization's enterprise resource pool, you don't need to create another resource pool. See Add resources to the enterprise resource pool for more information.

Your license (Planner and Project Plan 3 vs Plan 5) is not the cause of this limitation. Plan 5 adds advanced portfolio and enterprise resource management features in PWA, but it does not unlock local resource pool functionality. Local resource sharing is available in the desktop client when working offline.

For more information, please refer to Create and share a resource pool in Project desktop

To help narrow down the issue, could you please confirm these questions below to help me diagnose the issue more effectively: 

• When the issue occurred, were both files open in Project before you tried to share resources, or did you attempt to link them with only one file open?
• Were the files stored in a personal OneDrive or a OneDrive for Business/SharePoint library?
• Did you have any sync errors or pending changes in OneDrive at the time?
• Are you currently connected to Project Web App (PWA) or working in standalone mode?

Moreover, this behavior is often related to how Project interacts with files stored in OneDrive or SharePoint. When files are only available as cloud placeholders (via Files On-Demand), Project may treat them as unavailable or read-only, which disables the “Use Resources…” option in the Share Resources dialog.

By marking the files as “Always keep on this device”, you ensured that both the resource pool and the sharer project were fully downloaded and writable locally. This allows Project to establish the link between the two files without sync conflicts.

• Project needs a local path and full write access to both files when creating resource links.
• If OneDrive is still syncing or the file is opened directly from the web, the link operation can fail or remain disabled.
• For more information, please refer to Sharing Resource Issue

Note: To directly edit a resource pool file, you’ll need read/write access to that file. Otherwise, you can only view resource usage and make changes to your project’s resources.

Please understand that as forum moderators, our primary goal is to provide helpful guidance and support through general troubleshooting steps. While we don’t have access to internal systems or administrative tools required to resolve account-specific or backend issues, we truly appreciate your understanding of these limitations. We genuinely hope the information we share helps guide you in the right direction, and we're always here to assist as much as we can within our scope.  

I hope this information is helpful. Please follow these steps and let me know if it works for you. If not, we can work together to resolve this. If I misunderstand anything, please feel free to reach out.

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Thank you for your patience and your understanding. If you have any questions, please feel free to reach out.

I'm looking forward for your reply.

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Dear @Jim Lee,

Thank you for your update.

I'm glad that your issue has been solved. Therefore, I would make a brief summary of this post so that other forum members could easily find useful information here:  

Issue Description:

The “Use Resources…” option in Microsoft Project Online Desktop Client was greyed out when trying to link a local resource pool .mpp file to a project file. Initially, it appeared to be related to licensing differences (Plan 3 vs Plan 5) or machine configuration. Later, it was suspected that file access through OneDrive or the Recent Files list might be causing the problem.

Current Solution:

The issue was resolved by closing Project and reopening the files by browsing directly to their folder location, rather than using the Recent Files list. This ensured Project recognized the correct local paths and writable state, enabling the “Use Resources…” option.

• The Recent list may store a path that points to an older location (e.g., a OneDrive/SharePoint placeholder, a previous sync root, or a temporary path). If that path isn’t fully available/writable at the moment, Project can’t establish the resource link, and “Use resources…” may remain disabled.
• Clicking from a Recent entry can sometimes open the file in a different context (or an instance already holding a lock), especially if the recent entry originated from a web‑open flow. Browsing ensures a clean open in the current desktop instance.

Prevention Tips:

Always open files from their actual directory path. Ensure files are fully local and writable (use “Always keep on this device” if stored in OneDrive).

I hope this information is helpful. If you have any questions, please feel free to reach out.

Thank you for your patience and your understanding. I'm looking forward for your reply.

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