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iSystems protects their intellectual property by tying their software to an underlying physical computer with the use of a "computer modifier"; this 8-character code is used by their licensing system to keep things from running where they don't belong.

Table of Contents

When the modifier changes unexpectedly, some or all of Evolution will stop working, requiring a new license key from iSystems support, and this has been known to happen at highly inconvenient times.

While researching a customer who had sporadic and unexplained de-licensing issues, I was able to determine what goes into the modifier in order to see what changed between any two points in time. This paper summarizes that research.

What's in the modifier?

The modifier is an eight-character hexadecimal number (32 bits) that provides a "fingerprint" of the underlying hardware, and Evo's registration key is tied to it. This helps forestall theft of iSystems' software.

The modifier can be seen in the Evo Management Console after navigating to Configuration » License:

Evo MC showing modifier

These items go into the modifier:

  1. The registry key HLKM\Software\Microsoft\Windows NT\CurrentVersion\ contains to two strings values, RegisteredOwner and RegisteredOrganization, which both feed into the modifier. These are often set at OS-install time, and in older operating systems (XP, Server 2003) it shows up on the Properties page of My Computer, though it's a bit less obvious in newer operating systems:
    My Computer Properties showing RegisteredOwner and RegisteredOrganization

    Do not change these casually!

  2. The volume serial number of all fixed hard drives, but ignoring removable media. External USB drives are sometimes fixed and sometimes removable, so unless you know that it's removable, assume that adding a USB hard drive will change the modifier. USB flash/thumb drives are almost always disregarded as removable.
  3. The system Processor Type and OEM ID; these are typically set at installation time and are not typically changed (intentionally or inadvertently) by the user. It's not clear what purpose these values serve in Windows. The values for these fields is taken fromn the GetSystemInfo() Win32 API call.
  4. The address of the Ethernet card. This is determined indirectly, so it's not entirely clear how multi-NIC configurations are resolved into a single MAC address.

The evo-modinfo tool

In the cource of this research, I created a tool, evo-modinfo.exe, that reports the items that go into the modifier (though it does not compute the modifier itself). This program runs in a command window and reports this way:

evo-modinfo 1.0.5 - 2008-03-19 -

Report for computer "EVO2" run on: Mon Aug 20 20:26:36 2012


  Reg Owner        "Steve Friedl"
  Reg Organization "StevePay, LLC"
  OEM ID           0x00000000
  Proc Type        0x0000024a
  MAC Address      00-0C-29-D5-17-FF

  Fixed drives:
    C:\  serial 0x18D1F414

A typical practice is to save the output to a file (say, c:\bin\evo-modinfo.txt) to provide a baseline for comparison when asking "ok, what changed?". I make it a practice to install this on all customer middle tier machines in the C:\BIN directory.

This tool may be downloade from here.

Fixing broken modifiers

The modifier is used, of course, directly for licensing of the Request Broker, and if it changes, you must request a new license key from support, but it's also used in additional places in more subtle ways. Mainly, it's used in the password-encryption algorithm for middle-tier configuration files.

This section lists the areas where the modifier is used, what it looks like when it's broken, and how to fix it. But note that if a modifier changes on a machine, it breaks all the parts that use it (it generally won't be mix and match).

It's important to note that each machine has its own modifier, and not all Evolution services are affected. This table shows which Evo services use the modifier in one way or another.

Evolution service Modifier impact?
Evo Management Console YES
Request Broker YES
ADR Client YES
ADR Server YES
Evo Deployment Manager no
Request Processor no
Remote Relay no
API Adapter no

If a machine hosts only unaffected services, a modifier change won't have any impact (and probably won't even be noticed).

In this section, we'll use the hypothetical environment variable %EVO% to refer to where the Evolution services (but not the client!) are installed on that system. This is usually one of: C:\Program Files\Evolution or C:\Program Files (x86)\Evolution or perhaps installed on a different drive, such as D:\. This variable doesn't actually exist on the machine.

Generally speaking, when a modifier changes, the first thing you have to fix is the Evo MC login user, because all the other changes are done with that tool.

Passwords for EMC login users
The password for all Evo Management Console users are encrypted with the modifier, and when that changes, all the passwords are effectively invalidated, preventing you from logging in at all. You have to fix this before you can do anything else.
To verify and fix:
  • Using the browser, attempt to login to the Evo MC
  • If the usual credentials don't work, try user=admin and password=evolution
  • If none of them work, the modifier has probably changed.
  • To fix, in the Windows "Services" control-panel applet, stop the Evolution Management Console service
  • Using Notepad, edit the file %EVO%\ManagementConsole\EvMgmtCon.cfg. It will usually look something like this:
    admin=0100FFF4F03A157CCC80,3    «— delete this line
  • Save the file
  • In the Windows Services control-panel applet, start the Evo MC service again
  • In your browser, login to the Evo Management Console with user=admin and password=evolution
  • If desired, navigate to Configuration » MC Users and update the user accounts with new passwords
Encrypted Firebird passwords
When Evolution accesses the client files on the Linux database server, it does so via the Firebird user EUSER, and that account has a password. If the password is scrambled due to a changed modifier, Evo won't be able to access any database files.
To verify and fix:
  • Using the browser, Login to the Evo MC
  • Make sure the Request Broker is running
  • Nav to Configuration » Database Access:

    DB password entry field in MC
  • If the "EUSER password" field is blank:
    • Re-enter the password (it's usually pps97)
    • Click [Save Changes]
Note that the Firebird EUSER password is not something you ever use from within Evolution itself - it's strictly a server configuration matter.
Superuser account name
When Evolution needs to run key processes, such as an actual payroll, it switches internally to a "system user" that has rights to do things that the underlying user may not. The name of this user is encrypted, and if incorrect, generates a "Failed to switch to SU mode".
To verify and fix:
  • Using the browser, login to the Evo MC
  • Make sure the Request Broker is running
  • Nav to Configuration » System User:

    Evo MC showing System User
  • If the User field is blank:
    • Enter the superuser account name (usually super)
      (there is no password associated with this account)
    • Click [Save Changes]
Note: The name of the account is not at all security sensitive, so I've filed a feature request with iSystems to have them remove the encryption from this field entirely.
E-Mail configuration
When Evo needs to send non-VMR emails (such as errors from the the queue), it does so via the configuration in the Management Console, and if the SMTP account users a password, it's encrypted with the modifier.
Note that many SBs have email servers that do not require authentication, so the username and password fields are not used at all; this requires knowledge of your local configuration.
To verify and fix:
  • Using the browser, login to the Evo MC
  • Make sure the Request Broker is running
  • Nav to Configuration » EMail Notification:

    Evo MC showing EMail Notification configuration
  • If the Username and Passwords are shown with *****, then it's probably OK
  • If they are blank, either they're not required at all, or the modifier broke them. To find out, click, [Send Test Email] and see whether the users mentioned in the "Notifications are sent to" box receive the email.
  • If they were not received, enter the username and password if you know it, or see your local IT person for further troubleshooting.
Note that the configuration of VMR email is done from within the Evo client, and that does not use the modifier, so won't need to be updated. If the Evo MC email configuration is not working, it shouldn't imact Evo operations in a major way.
Invalid RB License
When the modifier changes, the Request Broker reports and invalid license (assuming the EMail configuration is set properly), and it won't allow any Evo processing to run. Evo is completely down in this case, requiring immediate action.
To verify and fix:
  • Using the browser, login to the Evo MC
  • Nav to Maintenance » Service Control
  • Stop all Evo services
  • Start the Request Broker
  • Nav to Configuration » License

    Evo MC showing bad license
  • If it shows License is invalid, a new license key must be requested.
  • Compose an email to iSystems support, including in your message:
    • Say explicitly that you're requesting a new license key
    • Note whether it's a test or a production environment
    • Include your serial number (from the MC License page). Production serials are in the form 10XXX, while test serials are in the form 20XXX
    • Include the "Computer modifier" shown at the top of the page, either copying-and-pasting to your email, or typing it very carefully. If the modifier is not correct, the license won't work.
    • A mention of whether you're down now or not (a test environment may not be time critical)
  • If you're down, perhaps followup with a phone call to support
Support will respond with an email including your license key, which is quite long and can only be reasonably cut and pasted into the Evo MC; it's best to perform the next step while you have the email from support available.
To apply a new license key:
  • Using the browser, login to the Evo MC
  • Make sure the Request Broker is running
  • Nav to Configuration » License
  • Copy (using control-C) the license key to your clipboard and paste (using control-V) into the Registration code field
  • Click [Save Changes]
  • Observe that the license errors went away and that licensed products are shown:

    Evo MC showing good license status
  • Stop, then start, all Evo services
  • Return to the Configuration » License page to verify all is well
  • Using the Evolution desktop client, attempt to login to Evo
ADR client or server configuration
Most Evo service bureaus run some kind of replication using the Evolution Asynchronous Data Replication, many to the iSystems hotsite. Some service bureaus also host their own ADR server.
All usernames and passwords used by ADR are encrypted with the modifier, and must be updated if the modifier changes. Not that many service bureaus run the ADR client and server on different machines from the
To fix the ADR client:
  • Using the browser, login to the Evo MC
  • Nav to Monitoring » AC Status
  • Verify service status. If it has a green check:

    Evo MC showing good AC status

    ... then all is well and no intervention is required.
  • If it shows a red X for the connection status:

    Evo MC showing bad AC status

    ... then the username and password for the ADR server must be re-entered.
  • To fix, nav to Configuration » AC Config:

    Evo MC showing ADR client config
  • Enter the username and password only, then [Save Changes]. Do not change the other values from what's there now, as the examples in this screenshot may not apply to your configuration.
  • Nav back to Monitoring » AC Status and verify that the service has reconnected (it might take a minute or so to reconnect; click the AC Status tab a few times to refresh).

Microsoft's KB2603229 update

A Windows Update published from Microsoft in late 2011 broke the modifier on 64-bit Server 2008 R2, but fortunately it's easy to work around if the workaround is performed before the update is applied.

On 64-bit operating systems, there's a separate (and parallel) section of the registry that 32-bit programs use, and for whatever reason, the RegisteredOwner and RegisteredOrganization fields in the 32-bit registry don't always match the corresponding values in the 64-bit registry. KB2603229 "fixes" this by copying the values from the 64-bit registry tree down to the 32-bit tree, and since Evolution is a 32-bit program, it sees this change and breaks the modifier.

It's hard to think of a Windows Update more narrowly tailored to breaking the Evo modifier than KB2603229, and it's unclear why this was an issue important enough to have an update in the first place.

In any case there are a number of approaches for dealing with it (all before the fact).

Even given these workarounds, it's wise to reboot the server after applying this (and other) Windows Updates, then verify that Evo licensing hasn't changed.

Timing of modifier changes

A complicating factor is that though the factors that go into the modifier are reflected immediately, the actual modifier is not recomputed until later, when the services that rely on them start. This means that additional modifier problems can lay dormant for some time even after they seem to have been fixed.

Scenario: if an unused network interface is disabled, it can impact the factors computing the modifier, but it won't have any immediate on Evolution.

But the next time the Evo services restart (perhaps while installing a routine update), the Request Broker and ADR services will both recompute the modifier and will require that they be relicensed and updated.

This could easily be a week after the change was made, making it difficult to find (or remember) the root cause of the change.

But we're not finished: if only the regular Evo services were restarted and fixed, the Evo Management Console has still been running from before the change, and since it's not restarted, it's still using unchanged passwords.

The next time the server reboots, the Evo MC restarts and finds the modifier has changed, and none of the MC user credentials work any longer. This can happen long after the original modifier problem was fixed, leading to an puzzling concern over how the modifier changed "again".

The only way to be sure that whatever has changed in the modifier has settled down is to reboot the server, which insures that all Evo services have restarted, as well as any OS changes (NIC changes in particular) have for sure been applied.

Best Practice:: If you discover that a modifier has changed, reboot the server if you can before querying the modifier and getting a new license key.

If rebooting at the moment is not practical due to pressing payroll work, at least stop and start all Evo services before collecting the modifier and relicensing. But: later, during the off hours, perform a full reboot of the server and verify that all parts are still working.

Modifier Tips and Gotchas

There are a number of surprises when dealing with the modifier that we hope to detail here.

First Published: 2013/04/17