Dates are showing asterisks, but have no constraints.

Check external early start first, then external late finish. These are constraints created by P6 when subprojects are imported separately. This feature is intended to preserve the dates calculations between networks. In your case, because the way you are working (separate files) after you receive al subprojects, you need to recreate the relationships between them and then delete the external dates. To delete external dates, show these columns (Dates section) on the layout. Then click on the cell to edit or delete using the backspace key.

Issue with Total Float calculating on Longest Path for LoE activities.

There is a documented bug that has total float calculating increased total float for LoE activities. There is an enhancement request to fix it and there are also workarounds.

DESCRIPTION OF ENHANCEMENT REQUEST: Ability for Level of Effort (LOE) activities to be excluded from the Longest Path like in P3.

Problem/Issue? LOEs and completed activities are included in the path in Project Management.

LOEs or WBS Summary activities will never be at the end of the float path (the seed most critical activity that begins the path), but if an activityhas predecessors or successors that are LOEs they will form part of the path.

POTENTIAL WORKAROUNDS: 1) Calculate 1 multiple Free Float Path on Schedule
Options Advanced tab and group layout by Float Path.

2) Run filter "Where Float Path equals 1"

Activities on Float Path 1 should be the same as activities on longest path
in P3.

ADDITIONAL INFO:
This makes some activities (which are not LOE) show up on the longest path even though they shouldn't.

BugDB:11874155

How to work with remote projects in P6 Professional?

You can "check out" projects so that they can be worked on remotely. Once a project is checked
out, it can no longer be modified until it has been checked in. In addition to checking in the project,
you may replace the existing project with the remote copy of the project by using the Import
wizard.

Check out a project

1) Open the projects you want to check out.
2) Choose File, Check Out.
3) Select the projects you want to check out.
To check out a project, it must be open. If the project you want to check out is not on the list,
click Cancel, open the project, and restart the wizard.
4) Type the name of the file and the location where the file will be saved.
5) Click Finish.
An XER file is created that exports complete project information to other P6 Professional or P6
EPPM applications.

View the check-out status of a project
1) Choose Enterprise, Projects.
A red checkmark displays beside any project that is currently checked out.
2) Choose View, Show on Bottom, Project Details.
3) Click the General tab, and check the status of the project in the Check Out Status field.
Privileged users can also change the status of a project in this field.
The Checked Out By field indicates the user that checked out the project.
The Date Checked Out field indicates the date and time the user checked out the project.

Modify check in update options
1) Open the projects you want to check in.
2) Choose File, Check In, then select the project you want to check in.
3) In the Update Project Options dialog box, select the layout you want to modify and click Modify.
4) In the Modify Import Configuration dialog box, select the data you want to modify.
5) Select the action to perform during the check-in process.
6) Mark the Delete checkbox to remove unreferenced data, data in the project you are updating
but not included in the check-out file, from the project.
7) Click OK.

Check in a project
1) Open the projects you want to check in.
2) Choose File, Check In.
3) Select the file you want to check in.
4) Double click the Import Action field to select how the project data is checked in.
Select Update Existing Project to update with any new new/modified date in the XER file.
Select Replace Existing Project to delete the existing project and replace it with the project
checked in from the XER file
Select Ignore this Project to not check in the project.
5) Select the data to check in by modifying the layout configuration in the Update Project Options
dialog box.
6) Select the currency for the projects in the Currency Type dialog box.
7) Click Finish.

Schedule Comparison (Claim Digger) is now in 16.1 Visualizer.

The Schedule Comparison tool that used to be called Claim Digger, is now housed in the 16.1 Visualizer tool that launches off of the P6 Client (Professional). You select it from the top menu. In the next screen you will select the project you want to compare and whether you want to compare it to a baseline or a copy of a project (most likely an earlier version since the "project" will be the current project). Credit to Randy Cash.