Running Outlook on the iMac causes the screen to flicker and eventually black out and reduce to half/split screen display.

Ok, keep me updated if your issue fixed by reverting back to 16.24 .

I have been running like this for some 5 hours and no issues -yet!

If re-appears, will post accordingly .

Really do not think it is a hardware issue .

Regards.

Alan.

Been running Outlook version 16.24 after reverting back from 16.25  for three days now and issue of screen flashing has not re-appeared again.

This fix applicable to a late 2015 27" iMac - whether this applies to laptops ,other iMacs of a different vintage  etc. I really do not  know,  but now fixed on my iMac .

Hi,

I tried the downgrade today on my Macbook Pro with external 4K Monitor. Sadly the flickering came back after half a day having Outlook opened on the external Monitor...

Ok, keep me updated if your issue fixed by reverting back to 16.24 .

I have been running like this for some 5 hours and no issues -yet!

If re-appears, will post accordingly .

Really do not think it is a hardware issue .

Regards.

Alan.

Been running Outlook version 16.24 after reverting back from 16.25  for three days now and issue of screen flashing has not re-appeared again.

This fix applicable to a late 2015 27" iMac - whether this applies to laptops ,other iMacs of a different vintage  etc. I really do not  know,  but now fixed on my iMac .

Disabling dark mode doesn't help, as i already had this problem before Dark Mode was introduced.

Just discovered that.  It started again and even without Teams running.

I have gone back to Outlook 16.23, but you have to go even further back before the problem is 100% eradicated, but 16.23 is much more stable.

Disabling dark mode doesn't help, as i already had this problem before Dark Mode was introduced.

Running Outlook on the iMac causes the screen to flicker and eventually black out and reduce to half/split screen display.

If I don't run the Outlook app the Mac runs like clockwork.

With Outlook active, at some point the flickering begins and then gets progressively worse until the screen is completed fuzzed or it pops back to a half black screen (which continues to flicker intermittently - more often than not)

Whilst it sounds like a hardware issue (and I've ordered a new Mac thinking it was!) it appears to be tied to Outlook.

iMac (Retina 5K, 27-inch, Late 2015)

3.3 GHz Intel Core i5

8 GB 1867 MHz DDR3

AMD Radeon R9 M395 2048 MB

Mac OS 10.14.1 (18B75)

Outlook 16.19

Rebooting seems to clear it until we run Outlook again, then the cycle continues.

Hi AussieFlem,

Can you please confirm if you have resolved this issue as we are experiencing exactly the same issue. We have taken the iMac to Apple and had the logic board replaced but still have this problem. Like you, we have narrowed this down to Outlook causing the problem and none of the updates have fixed it. This issue definitely started after an Office update a while back. I have also completely wiped the drive and reinstalled everything from scratch (not a restore) so the issue would appear to be with Outlook and not hardware or preferences.

Please do update as I don't know what else to try!

Thanks, Luke.

I have had this problem ever since Dark Mode was introduced in Outlook.  I used Time Machine to restore an older version of Outlook and never had the issue again.   However since the latest upgrade of Outlook the problem has returned.  I can log out and the flashing stops and then log back in.  I can change the resolution and the problem stops and then change the resolution back.  But th eporblem only happened when running outlook.    If I don't tun Skype for business it does not have an issue, but we have just moved to Teams, and the combination of teams and Outlook also causes the problem.   I have just noted at the tail end of the post that disabling Dark Mode in Outlook sorts it, so I am trying that.   I have looked at the LOGs on my Mac at errors and can not see anything obvious, so it is very frustrating.  I have exactly the same machine specification above.