Processing 4.4.10, 'Syntax Error'
Hey all,
I’m trying to run the GUI with Processing v4.4.10, but it’s not working.
Here are the errors that pop up:
I used to work with Processing 3.5.4, but it was crashing sometimes, so I wanted to update to see whether the problem could have been fixed.
Some details:
- Java environment has been updated.
- All the libraries of the Sketch have been copied into the Processing folder.
- Nothing change whether I run it as admin or not.
- I am on Windows 11.
Can someone help?
Thanks for the support! 
Comments
Hi Micaela,
The documentation says that Processing 4 is supported.
https://docs.openbci.com/Software/OpenBCISoftware/GUIDocs/#running-the-openbci-gui-from-the-processing-ide
Are you sure you are installing the 3rd Party Libraries, as mentioned in the section:
https://docs.openbci.com/Software/OpenBCISoftware/GUIDocs/#downloading-the-code-for-the-openbci-gui
In your screenshot, the error you point to is in the ControlPanel function, which imports a whole bunch of 3rd Party Libraries from outside OpenBCI sources. If you do not have those located in the correct folders, then Processing will give up saying it cannot complete the 'method declaration'.
https://github.com/OpenBCI/OpenBCI_GUI/blob/master/OpenBCI_GUI/ControlPanel.pde
[GUI ControlPanel source code, see the many 'Import' lines at the top]
Mentioning Richard @retiutut, who is the OpenBCI_GUI dev.
Hi @wjcroft,
Thank you for your help.
Yes, I tried it several times, including re-downloading everything multiple times, but nothing has worked so far...
In order for Processing to FIND the 3rd party libraries, they must exist in certain SPECIFIC directory folders, as mentioned in the document. Did you check to see those folders exist, and have the libraries? Is it possible there might be some kind of permissions or ownership issue preventing Processing from loading the libraries?
FWIW I am having the same problem on processing and copied the libraries into the processing folder.
Hi Richard @retiutut, do you have any insights? Now TWO users are reporting same error messages? I'm surprised they are seeing 'Syntax Error' (screenshot above), and not something like undefined function?
I got the same problem.
I have the same issue it seems, but here's my error:
I've created an issue for this in the Documentation. I'm about to push a change to specify that we still use Processing 4.2 as of January 2026.
There was a huge change/gap/leadership/etc. thing that happened between 4.2 and 4.3. I also began to notice subtle breaking changes in the drawing of text and it's location. Since then, and even in the upcoming GUI v7 release, the GUI still uses Processing 4.2.
Side note: GUI v7 can be previewed from source in the
developmentbranch.https://github.com/OpenBCI/Documentation/issues/296
Processing 4.2 download - https://github.com/processing/processing4/releases/tag/processing-1292-4.2