I had random crashes while trying to use the GDL Text I/O -addon with a custom object. The object would read a tab separated text file into three variables declared in the script.
It turns out the addon would actually read in a string from column that exceeded the max number of chars defined in GDL specs. I'm suspecting this was what made ArchiCAD crash. As soon as I limited the column string length into 255 (the columns are exported from excel), the crashing stopped.
I was even able to print out the string length within the GDL using STRLEN(), and it really showed a string length bigger than 255. (314 I think, to be specific).
I'm using ArchiCAD 15 FIN Full 4056 with Windows 7.