The Problem
When Running the Lync Server Deployment Wizard – Install oe Update Lync Server System – Step 2: Setup or Remove Lync Server Components I get an error immediately after Disabling unused roles

The Error
Input string was not in the correct format

at System.Text.StringBuilder.AppendFormat(IFormatProvider provider, String format, Object[] args)
at System.String.Format(IFormatProvider provider, String format, Object[] args)
at Microsoft.Rtc.Internal.Tools.Bootstrapper.BootstrapperTask.OutStatusLine(String format, Object[] args)
at Microsoft.Rtc.Internal.Tools.Bootstrapper.BootstrapperTask.DeactivateRemovedRoles()
at Microsoft.Rtc.Management.Internal.Utilities.LogWriter.InvokeAndLog(Action action)

The Culprit
This turned out to be the Lync Admin account, I couldn’t find any evidance pointing me to the cause other than a feeling of discomfort with the format of the Lync Admin User account name.
The Lync Admin account was similar to this:
{LyncAdmin}

Couldn’t find any documentation saying the curly brackets may be an issue, but tried with an account that had a simpler format and the required permissions and tada…

The Solution
Initially I had the account renamed to something like LyncAdmin but it still misbehaved, recreating the account without curly brackets did the trick