Say goodbye to CReg?


Two  days ago about I wrote about CReg/Vreg because I anticipated the fix coming in March’s OS rollup.  So surprise!  The following day we get fixes a month early.

CReg/VReg and 1703/1709 App-V

The totality of information coming from Microsoft about the changes are included in the KB article for the February rollup for Windows 10 1709: These fixes are distributed as part of the general OS non-security patches for the OS.

Related to App-V are the following items [my comments in italics]:

  • Addresses issue where the App-V client didn’t read the policy for SyncOnBatteriesEnabled when the policy was set using a Group Policy Object (GPO).  [Affexts the App-V Client on laptop/notebook/tablets that use the App-V Management Server to do publishing.  Without the fix, devices not connected to power would inadvertently perform a publish synch on the normal schedule set with publishing].
  • Addresses issue where the Supported On field for the Enable App-V Client policy is blank in the Group Policy editor. [Fixes issue with GPEdit].
  • Addresses issue where the user’s hive data in the registry is not maintained correctly when some App-V packages belong to the connection group. [This may or may not be related to CReg.  My guess is that it is unrelated, but people affected it were also hitting CReg issues which confused things].
  • Provides additional logging for administrators to take action, such as picking a proper configuration for their App-V package, when there are multiple configuration files for a single package. [The Windows 10 implementation removed a lot of the event logging and it has been more difficult to diagnose issues. More logging is appreciated].
  • Addresses issue with App-V packages that aren’t compatible with registry virtualization using kernel containers. To address the issue, we changed the registry virtualization to use the earlier (non-container) method by default. Customers who would like to use the new (kernel container) method for registry virtualization can still switch to it by setting the following registry value to 1:
    • Path: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\AppV\Client\Compatibility
    • Setting: ContainerRegistryEnabled
    • DataType: DWORD

This last item formalizes the temporary workaround that we previously had for the CReg issue.  As Microsoft made VReg the default, we can infer one of two things:

  1. Microsoft is giving up on CReg, but is leaving it in the system because only some packages expose the problem.
  2. Microsoft will need to make additional fixes to CReg to make it work, and might revert the default back once they are comfortable.  This option will make more sense than it does at the moment if we discover additional fixes are already included that not mentioned in the KB. It’s not like that’s never happened before.

At this point I would recommend moving back to VReg to all App-V customers, including those that have not implemented the temporary fix. My gut feeling is that CReg is probably dead and you don’t want to be on it.   I’ll update the post if that changes.

Categorized as AppV5

By Tim Mangan

Tim is a Microsoft MVP, and a Citrix CTP Fellow. He is an expert in App-V and MSIX.