Installing Test Font Error

[ifthenjim]

When trying to generate a test install I continue to get the following error

"Failed to generate the font for test install
Traceback (most recent call last):
File "/Applications/RoboFont.app/Contents/Resources/lib/python3.7/fontTools/ttLib/tables/_h_m_t_x.py", line 100, in compile
struct.error: argument out of range

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "lib/doodleDelegate.pyc", line 188, in testInstallFont_forWindow_showProgress_option_
File "lib/fontObjects/doodleFont.pyc", line 300, in generate
File "lib/fontObjects/doodleLayer.pyc", line 388, in generate
File "/Applications/RoboFont.app/Contents/Resources/lib/python3.7/fontCompiler/compiler.py", line 149, in generateFont
File "/Applications/RoboFont.app/Contents/Resources/lib/python3.7/fontCompiler/baseCompiler.py", line 379, in compile
fontTools.ttLib.TTLibError: 'hmtx' table can't contain negative advance widths

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Installing Jakob Modern Regular failed
The file does not exist at the specified URL.
--------------------"

[roberto arista]

👋

is the issue solved?
did you check if you have any glyph with a negative width?