Text in Navigation Pane turns white

I assume you mean the reverse triangle in the Documents Map.  I can't recall from earlier if that created the problem, so I just tried it now. In this current test, clicking on the triangle did not create the problem (that's not to say it might not have created it previously, but if so I don't remember).  I thus created the white text using the method I described above (going back and forth between the Thumbnails Pane and Document Map until it appeared), and then tried clicking on a reverse triangle.  Each time I did this, the text revealed by the triangle briefly flashed black before it went back to white. 

I can add two other things I noticed:

1. Yesterday I was changing the outline levels of some of the text in the document, to adjust how it appeared in the Documents Map.  As I was doing this (i.e. I was working in the document, not in the Navigation Pane), the text in the Documents Map would frequently go white, necessitating I restore it to black using the method I described earlier (clicking on the Reviewing Pane Tab and then back on the Documents Pane Tab).
2. The white text is not restricted to the Documents Map.  Rarely, it also appears in the Navigation Pane's Find-and-Replace dialog—see screenshot below (the word in white is "dantain"):

Hi Theorist9,

Thanks for your updates.

I’d like to confirm whether you can reproduce the issue via clicking the reverse triangle in the affected document.

Thanks,

Cliff

I tested with the “test document” but cannot directly reproduce the issue. By “click back and forth between the Document Map and Thumbnails Pane”, do you mean click that two tabs until the issue occur?....

Meanwhile, your Word version is 15.31. Does the issue occur in the earlier version (Mac OS or Office suite) on your device? ...

As you know, the issue is with the Document Map.  What I meant is that I switch to the Thumbnails Pane and then back to the Document Map (by clicking on their respective tabs). I keep repeating this cycle until the Document Map shows white text (generally I only need to go through a few cycles to see it).  I.e.:

1. Start in Document Map
2. Click on tab for Thumbnails Pane.
3. Click on tab for Document Map.
4. Glance at Document Map to see if text is white.  If not, keep repeating steps 2 through 4.

Hopefully this description is clear enough that I don't need to supply a video. 

I can't say if it occurs in an older version of Word; I've only noticed it with the current version, but it's probably only with the current version that I've used the Document Pane extensively.

I'm afraid I don't currently have the time to set up a new Office 365 account.

Hi Theorist9,

Thanks for replying to our private message.

I tested with the “test document” but cannot directly reproduce the issue. By “click back and forth between the Document Map and Thumbnails Pane”, do you mean click that two tabs until the issue occur? If it’s convenient, could you record a video for your reproducing this issue with this method? You may use a mobile phone and then upload the video via replying to Cliff’s private message.

Note: I noticed that in your first reply, you mentioned there are several methods to reproduce this issue. You may record them in video. It will help us reproduce the issue from our side.

Meanwhile, your Word version is 15.31. Does the issue occur in the earlier version (Mac OS or Office suite) on your device? You may alsocreate a new account, and then check if the issue can be reproduced with the new account profile.

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Best regards,

Tim