I have a clean, patched full install of BG + TotSC under "D:\Games\Black Isle\Baldurs Gate 1"
Equally clean and patched full install of BG2 + ToB under "D:\Games\Black Isle\Baldurs Gate 2"
(Keeps them sorted in the directory tree, the missing apostrophe in "Baldurs" is the BG2 installer's fault. I just rolled with it.)
Game disc is out of the drive. BGT starts up fine, I install the core, and I input my BG path as prompted.
Setup commences, it extracts and copies over the CRE files, then something goes awry:
------------------------------------------------------------ Extracting texts for translation from Baldur's Gate:TotSC... ------------------------------------------------------------ [_weidu] WeiDU version 22900 [D:/Games/Black Isle/Baldurs Gate 1/Chitin.key] 159 BIFFs, 16694 resources [D:/Games/Black Isle/Baldurs Gate 1/Dialog.tlk] 24124 string entries [_weidu] Using scripting style "BG1" Baldur's Gate installation directory detected as "D:/Games/Black Isle/Baldurs Gate " The system cannot find the file specified.Somehow the 1 got truncated off the path at some point, and the remainder of the install is interspersed with various renditions of "file not found".
(For the record, I tested on a clean BG2 install after a general failure on a slightly-modded one.)
Once I discovered this in the log, I reverted the installation as instructed, renamed my BG folder to "D:\Games\Black Isle\BG1". After running the setup steps again, with this new path, everything installed perfectly.
I wouldn't think the path length is an issue. (it would be even longer in the default Program Files path.) But having no knowledge of WeiDU's internals, I won't try to speculate.
I have the error-wracked SETUP-BGT.DEBUG and SETUP-BGTDOS.DEBUG saved, if needed I can upload them.