Empty frozen pop-up window remains after closing FlexSim 25.2.0

[borja_lorenzo]

Hello,

I would like to ask if anyone else has experienced this behavior in FlexSim 25.2.0.

Occasionally, and apparently randomly, an empty pop-up window remains floating on the screen. In the screenshots, it happened with a trigger/code editor window, specifically **Source2 - On Creation**, but I have also seen similar behavior with other types of windows, such as the Experimenter window or list entry/editing windows.

The issue is that the window becomes completely empty and frozen. It cannot be moved and it does not respond to the usual window commands such as minimize, maximize, or close. Even if I close FlexSim, the empty window remains visible in Windows and only disappears after restarting the PC.

I am attaching screenshots showing:

• the empty frozen window while FlexSim is still open
• the same window still remaining on the desktop after closing FlexSim.

I have not been able to reproduce the issue consistently. If I open the same window again from FlexSim, it normally opens and closes without any problem.

I have also experienced this behavior with different FlexSim files, so I do not think it is related to a specific model file.

Has anyone else experienced something similar with version 25.2.0?

It does not seem to be related to the model logic, but rather to a graphical interface or pop-up window handling issue.

I am attaching my device specifications.

Thanks in advance.

[Jeanette_Fullmer]

Hello @borja_lorenzo,

I have experienced this issue. I also have not been able to reproduce the issue as well. I can create a report for our developers, however I am not sure how much they can investigate considering we do not have steps to reproduce the issue. [FLEXSIM-13269]

When you see this, can you look into your task manger and see if there is a FlexSim process that is still running that needs to be closed?

[borja_lorenzo]

Thank you for the update.

Just to make sure I understood correctly: if the issue happens again, I should not restart the computer immediately. Instead, I should first try to close the main FlexSim window and then check Windows Task Manager to see whether any FlexSim process is still running in the background.

If there is still a FlexSim process running, I will take a screenshot and then try ending the process manually to confirm whether the frozen window disappears.

As additional context, in all the cases where I have experienced this issue, the frozen windows were related to simple standalone windows, mainly list windows and Custom Code windows. They were not docked or grouped windows.

If the issue happens again, I will try to collect:

• a screenshot of the frozen window,
• a screenshot of Task Manager showing whether FlexSim is still running,
• the FlexSim version,
• and the type of window I was using when the issue occurred.