guestScriptManager error : "The guest authentication that is being used does not have sufficient permissions to perform this operation"

Hello,

I've been trying for several days to create a workflow to automatically delete E1000 adapters on a VM and replacing it with Vmxnet3 while conserving the adapters network configuration.

Everything is working fine with Linux VM (as the configuration is automatically kept) but I've got an error on Windows VM where I have to launch a Powershell script (tried with batch script too) with the guestScriptManager package.

Every script I try to launch on a Windows 2008R2 VM fails at the same step : Create temporary file in guest. The error : "The guest authentication that is being used does not have sufficient permissions to perform this operation (Workflow:Create temporary file in guest / Scriptable task (item1)#8)"

Strangely, I'm able to launch a script one or two times just after a VM deployment and then I'm stuck with this error.

I've tried with local and domain Administrator with no luck. I have no other description or log on the error...

Any help would be appreciated

Thanks