OTS parsing error: OS/2: Failed to parse table

[Vitalius1]

The error in the screenshot started to appear as soon as our company's proprietary icon font added some new icons mapped to the Supplementary Private Use Area-A code points (we ran out of the PUA code points 😄 ). We use this library for subsetting and you can see in the screeshot the new icons are rendered as a rectangle and the character next to it being the last number in the hexadecimal represenation of the code point it maps to. A quick fix would me much appreciated... Thanks!

[Vitalius1]

Here is an output of the Font Validator tool I found here