One of my fonts (graphic elements) causes this error while being run through a program to check compatibility:
OTS ERROR::GSUB: bad offset in GSUB header, table discarded
First of all, what is dsub table?
Is there a way to remove it completely (if it’s not used)?
You mean GSUB. It is the table containing the OpenType feature. So you would not like to remove it.
What program did the error message come from?
GSUB is short for glyph substitution and includes all substituting features, like ligatures, contextual alternates, or stylistic sets.
Does the error still occur if you update and recompile features?
The error message might be a mere warning. Do the substituting features work in InDesign?
there are no substitutions. the font works perfectly in InDesign.
there are only graphic elements such as flowers, borders, banners etc, no letters in the font…
rebuilding the features doesn’t solve the problem. 
Can you open the font in OTMaster, and see if a GSUB table is there? Or send me the Glyphs file?
And which app gives you the error report? Font Validator?
i don’t have OTMaster (unfortunately)
What is the email to send the font to? support-at-…? or another one?
Have no idea which app gives the error. It’s not me, it’s Linotype who runs the font through the programm…
We had a similar error recently. The problem is with makeOTF that is compiling the GSUB table. It doesn’t seem to impact the font, at least not in Indesign. Can you get me in contact with the people at Linotype that told you about the error?
I’ll email you. Email is still the same - support_at … (removed)
Upd: just emailed it.
I have a look asap.
FWIW there is a free version of OTM that lets you open a font to examine tables. It’s great for troubleshooting.