I haven't seen it myself but it looks like a library part is trying to open a text file that hasn't been properly closed (probably by the same part). The easiest thing is if you can guess which part might be trying to open the file (it's probably not a GS part). Otherwise you can do a binary search (try it by halves until you narrow it down).
I think library part and GDL aren't properly saved to net work system on my computer, then when I wanted to try on my collegue's computer at work, txts are missing on my library part. (the problem is still mysterious for me though, as me not an expert on Archicad)
any way, problems solved when I get back on my computer at work.