Here you get a "fine" sample: _ALLG.zip
Inside you will find a sample tree with only one 2-byte-file in the deepest path.
Please unpack my archive direct to root of some (subst) drive for same conditions.
On my server 2008r2 and also Win7/x64 PC I get
- crash for subfolder F:\_ALLG\EEE\_Weiterbildung\1 or higher
- no crash for subfolder F:\_ALLG\EEE\_Weiterbildung\1\Buecher_Skripte
- no crash for subfolder F:\_ALLG\EEE\_Weiterbildung\Buecher_Skripte
So my (maybe too) simple suggestion is, you use relative paths and if I navigate one level back, the length-sum of all strings will be a lot lower.