This is possibly the simplest and most reliable way to extract the info necessary to understand the crash without too much guesswork:
If you go through the following to obtain a memory dump generated during the crash, someone may be able to tell you why Explorer is behaving that way:
1) Download and install either the 32-bit or the 64-bit "Debugging Tools" package, depending on your OS type: Debugging Tools for Windows - Overview
2) Open a CMD prompt and CD to the folder where you installed the debugging tools.
3) Run this command: cscript adplus.vbs -crash -nodumponfirst -minionsecond -quiet -pn explorer.exe
4) Reproduce the Explorer crash.
5) Find the new folder in that same location with a DMP (memory dump) file.
In that dump folder you may find 2 DMP files:
1) A massive one (hundreds of MB) with "1st_chance" as part of its name.
2) A much smaller one (few MB at most) with "2nd_chance" in the name.
It's (2) that I'm primarily interested in right now. Zipped up, that file may only be a few hundred KB in size - small enough to upload here.