There are some core softwares come with the OPEN AT 3.02.
If you go with the +WDWL procedure, you should upgrade the wdwl program first, so download the dwl.dwl file. (check the version with AT+WDWL?) After then you can download 651__full_q2406b.dwl binary file (if you check the binary file more closely, you can see there are actually two, for A and for B memory modules) together with 651__w.dwl eeprom file.
The dwlwin procedure: First of all, you should also send the w.e2p files.
In the dwlwin doc, there is something about “BAD SOFTWARE” message:
From this i think that means wrong dwlwin downloader has sent to the module, and probably that put the files to wrong adresses. But, this feature is removed from version 3.3.7.
I would send the pro-dwl.wpb file together with q2406b.e2p and w.e2p again and for sure select the wismo 2-3 type instead of auto detect.