FF oddity

[#1]

Latest FF (v27.0.1).
As usual the memory leakage crept up so I quit from the task bar so that all windows and respective tabs can be re-opened.
On re-opening I found that two windows and their tabs opened as normal but two others opened with just icons and no text in each tab (see screen shot).
If I drag an offending tab to a new window then the text is back but drag it back to it's original window and it disappears again. All other aspects seem to be the same as before except (although it may be my imagination) the tabs without text seem to take slightly longer to load.
Anyone else noticed this?

[#2]

Short answer.... don`t know....
Question.... Why do you "need" all those tabs? 
Don`t use tabs myself... although I do sometimes have several different "windows" open on different websites which are listed along the bottom tool bar.... ( so I suppose similar to tabs ? ? ?)
Don`t have any problems with FF 27.01, or indeed any previous versions...
Maybe it is because you have all those tabs on the same website causing the problem?

[#3]

I doubt if it is the number of tab or even tabs for the same website as I have been using FF this way for as many years as I can remember (well, since they started doing tabs) without this issue.
Of course, they may have changed the way the tabs work and it could be some conflict with TabMixPlus.
Edit: I disabled TabMixPlus then re-enabled, quit FF then restarted and all windows/tabs appeared back as normal. Doesn't actually prove TMP was the culprit, though.

[#4]

Ah well............. at least you have sorted it ....... for now ! ! 

[#5]

...or till the next update
It wasn't a major issue but I don't always recognise the icons displayed in the tabs but I do understand the text