Cum Update 2018-02 causes multiple Powershell crashes

spilly · 24 Mar 2018

A friend has had nearly 3000 Powershell crashes logged ever since build 16299.248 was installed.
Powershell crashes spontaneously, possibly when a background task starts. I believe build 248 has introduced a new bug.

Q1) Does anyone have a suggestion of the cause or how to make the system more usable? (logs attached)
Q2) Should I report this as a bug? If so, where and how?
Q3) Do I just have to wait and hope MS will fix this in a future WU package?

Details: Each crash causes an on-top error window "Powershell has stopped working", which has to be closed manually.
If PC is left idling, on resuming there can be a stack of 10 or 20 such windows to close.
I'm pretty sure KB4074588 build 248 is responsible. If build is 248 or higher, new error windows happen spontaneously throughout the session; with build 192, no error windows occur.
As this is W10 Home, WU promptly re-installs the full current Cum Update, with a pending restart to complete the installation, so we can't escape the hassle. (The actual user is relatively inexperienced.)
Prior to 2018-02 there were no problems of this kind.

The system is used for email, browsing, MS Office and Skype.
System: Win 10 Home 64bit on Dell Inspiron 17R 5720, Intel Core i5-3210M CPU @ 2.50GHz, 6GB RAM, 1x1TB HDD for data + 1x120GB mSATA SSD as system disk; integrated Intel HD Graphics 4000

Actions taken: I googled, but didn't find any similar PowerShell crash cases; Ran Mem test; CHKDSK C: /F /R; SFC /scannow; DISM /Online /Cleanup-Image /RestoreHealth - all passed OK.
Uninstalling Cum Updates back to build 16299.192 seems to fix the problem; Reinstalling any Update after build 192 brings it back immediately.

Attached Documentation: Zip containing
1) Event log (< 40 events logged), from restart to first error window
2) Contents of %ProgFiles% WER folder related to this same error

spilly
NB I posted this issue in General Maintenance here a couple of days ago, before I discovered this is a Windows Update issue. Is there a way I can move my thread to a better forum if I've posted to the wrong one?

spilly · 27 Mar 2018

It turned out not to be a Windows Update issue after all, despite appearances to the contrary

I had an excellent chat session with Microsoft help, first line and second line support.
Finally tied the problem down to a rogue Javascript scheduled task. Disabling the task cured the problem.
The task was associated somehow with Trusteer Rapport, but does not exist if Rapport is properly configured.
So I have no idea how this all happened last February.

spilly