Reproducible crash of exlorer.exe with validation of folder backup

I am running Win 8.1 Pro 64-bit

TI 2015 current version (update 2).

Issue is reproducible with this version and previous version with folder backups only.

If doing folder backup with validation pass the following behaviour occurs:
- backup operation works
- validation pass commences
- in Win task manager - explorer.exe starts hitting ~ 14-15% CPU utilisation
- eventually, task bar becomes unresponsive and explorer.exe crashes
- only way to interact with PC is CTRL-ALT-DEL and signout and then sign in again

This is reproducible at will and the only way to stop the crash is to remove the validation pass. With no validation pass, backup completes successfully and explorer.exe does not not get anywhere ~14-15% CPU utilisation

No problems doing validation for disk / partition backups only folder backups are the problem.

Any suggestions to get around this issue please?

Even if I try a validation of a folder backup later it still demonstrates the same issue!