Avatars flashing on and off on Mac

All the avatars have been disappearing and reappearing every second or so for several months, although everyone’s bikes seem to keep moving and my progress seems normal. This persists despite my attempts to set the Zwift screen view density (high/med/low) in the Menu.

I’m using an older iMac and the Zwift updates all install without a hitch. Is there any way to increase the memory allocation to the program? I can’t think of what else might fix it.

Riders disappearing and reappearing is typically the result of a bad network connection. How are you connected to the internet?

That’s a thought Lin, although it’s a relatively new problem. I’ve been riding in the basement and use the Xfinity pod repeater. No problem with network access on the TV.

I wonder if Zwift made a change in the way they get or process network signal? Does the IT group monitor this forum?

I would take the log file and load it into Zwiftalizer which should probably give you a better idea of whether it’s the network or whatnot.

Whether or not your TV has network access is mostly irrelevant. You could stream video to your TV or even your iMac and never have a problem, yet still have issues w/Zwift. Depends on buffering and protocols in use. This applies even if Zwift never made a change.

Again, check out Zwiftalizer.

i am having the same issue and i have excellent internet connection/speed. Would welcome any suggestions.

perhaps it is the graphics card?


It’s still not clear but access to the graphics card on the Mac is limited. I ran the Zwiftalizer at Lin’s suggestion without seeing any errors. My network is not broadcasting on Channel 10 (the frequency Ant+ uses). I’m hoping one of the Zwift IT group has an idea.

@Rick_Kenney_DIRT What version of Mac OS are you using? I believe at this point, you need to be running at least High Sierra.

@Chris_Barnes2 Some more details would be useful, e.g., Mac type, OS version, etc…

Hi - i’m using iMac OS 10.11.6

thanks for your help

That’s really old. There have been five versions since then not including all the patches. I believe that is the last patch version for El Capitan (10.11.x). Depending on the age of your iMac you may or may not be able to upgrade to Sierra (10.12.x) or maybe even High Sierra (10.13.x). See if you can upgrade the OS. If so, I would recommend upgrading the OS to whatever version it will allow.

hi thanks for the quick reply. it is old (2009) and can’t update any further.

processor is Intel Core 2 duo

graphics NVIDIA GeForce 9400 256 MB

i have about 40G if free storage capacity.

I am having the same problem. Same computer. I’ve been running Zwift successfully on this computer without any problems for years. Did you determine what the problem is?

If the avatars disappear but you still see their bikes the problem is that your computer is struggling to render the avatars and simply doesn’t. This could be a sign that your computer isn’t powerful enough anymore.

If both avatars and bikes disappear it is network related. It could be your local network, at your network provider, or wherever between the Zwift servers and you.

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It’s a 2007 iMac and just the avatars blink. I’ll see if I can give the program more memory. I can’t upgrade the system software anymore but it’s still functional for now. Thanks!


Wow! I’d say you’re borderline not being able to run Zwift assuming it still runs now. Zwift has been really great about staying compatible w/older hardware over the years, but 2007 is quite old by computer hardware standards.

I’ve had Macs since the very first 128k in 1980! They seem to keep on working somehow. I’d hate to buy something new just to run Zwift in my basement. :wink:

At some point you will have to upgrade the software get more complex and need better hardware.