User Tools

Site Tools


Get the Most Out of Your ERP

The Windward Professional Services Catalog

Our catalog of services has topic-based, role-based, or technical plans that can help you maximize your software investment.

Follow Windward Software

New Feature Round-up

Intermittent 161 Errors in a Terminal Services Environment


Pervasive 161 error when logging into System Five in a Terminal Services Environment where the clients log into a TS Server and the data resides on a Data Server.

Pervasive Server is installed on the Data Server and Pervasive Client is installed on the TS Server.

If there are 15 Terminal Services sessions, 15 workstations that access System Five and 15 pervasive client licenses, then there shouldn't be any issues.
However… If the Terminal Server has 16 or more user licenses, but there are only 15 Pervasive Licenses you will likely experience 161 errors.

In this scenario:

The client had :

  • 16 Terminal services sessions
  • 15 Pervasive Client licenses
  • 15 System Five licenses.

- The Pervasive Server license was installed on the Data Server as a service, which is correct. Nobody would normally be logged into the server, but it will be running and sitting at the log in screen.

  • The Terminal Services server has the Pervasive Client installed.

Here is where it became interesting.

  • The Pervasive Client was installed as a service.
  • This would mean that when each user opens a Terminal Services session, a client license will be taken.
  • The last person to log into a Terminal Services session would not be able to log into System Five, even if there was an available terminal. This is because the first 15 Terminal Services sessions have already taken the 15 Pervasive Client licenses.
  • If all 15 users that normally logged into System Five were the first to log into terminal Services, everything would appear to be ok.

So what this means is that two sessions would essentially be playing musical chairs to see who gets the last seat.


We uninstalled the Pervasive Client on the TS, then re-installed it making sure that we installed it as an Application.

This was because logically, if it is installed as a service, the Terminal Services session would take the Pervasive license when the user logs into it.

But If it is installed as an application, System Five is the one that would take the Pervasive license.

I Tested this theory on the customer having the issue, and it worked. All 16 TS sessions are open and System Five is up and running in all 15 System Five sessions.

We further tested this theory by:

  • Logged out of System Five on one of the System Five sessions
  • logged out of that Terminal Services session
  • log into Terminal Services on the computer that doesn't have System Five installed.

At this point we had 15 terminals logged into Terminal Services, but only 14 terminals logged into System Five.

  • We then had a System Five user log into the 16th Terminal Services session, and we were able to log them into System Five without getting a 161 error.


So to prevent these type of issues in an environment where there are separate Data and TS Servers, Pervasive MUST be installed as an Application .

Created by Steve Wind October 5 2018

161_pervasive_error_terminal_services.txt · Last modified: 2018/10/05 16:23 (3 years ago) by swind