Gui Freezes “Get fields” freezes Hop GUI on Linux (Ubuntu)

[arunkumarArunachalam1]

Hi everyone
I’m facing a recurring GUI issue with Apache Hop 2.16.0 on Ubuntu Linux and wanted to check if others have seen the same behavior

Environment
OS: Ubuntu 24.04.3 LTS (Noble)
CPU: Intel® Core™ i5-8350U @ 1.70 GHz
RAM: 15 GB (swap enabled: 15 GB)
Java: OpenJDK 17
Apache Hop: 2.16.0

What happens

When I click “Get fields” in the Microsoft Excel Writer transform, the Hop GUI often becomes unresponsive and the OS shows a Wait / Force Quit dialog. In some cases, the process is killed.

This mostly happens when the pipeline has multiple upstream transforms. Simple pipelines like Table Input → Excel Writer usually work fine.

this is my Pipeline

Console warnings

I consistently see GTK/SWT warnings like:
Gtk-WARNING: Negative content width -1 (GtkScrolledWindow)
Gtk-CRITICAL: gtk_box_gadget_distribute: assertion 'size >= 0' failed
Killed

Question

Has anyone found a stable way to use “Get fields” in the Microsoft Excel Writer on Linux without the Hop GUI freezing?

Specifically:

• Are there any recommended JVM, SWT, or GTK settings to avoid this issue?
• Is this a known SWT/GTK limitation when rendering metadata-heavy transforms?
• Are there any best practices or official recommendations for handling Excel Writer metadata on Linux?
• Is there any plan or workaround in newer Hop versions to improve GUI stability for this case?
• Any guidance, confirmations, or alternative approaches would be greatly appreciated. Thanks!

[dmainou]

How many rows are you pulling from the table?
and how long until your sort finishes?
getting fields is easy if you've been testing the pipeline at every step.
i.e. the metadata has been read.

In sum it may not be the last step but everything preceding it.

[arunkumarArunachalam1]

Find the attach Screenshot for the
Rows counts and detiled view about the pipeline
if i click On get feild in excel writer started freezes

[hansva]

This will probably be caused by your table input transform, when pressing get fields we will refresh the field definitions.
In case of your table input, we will execute the query you have configured with a "LIMIT 1" to only fetch one row. But if this is a query that takes a while before that 1 row is returned you could end up in a frozen UI.