Describe the bug/To Reproduce
Placing ME controller, ME security terminal, ME wireless access point on an active cable it will turn into no texture after a few seconds.

If placed somewhere not connected it will remain with the correct textures.

After the forced crash (F3+C) it seemed to work, not able to let it break again, however I had this issue over multiple days.

Expected behavior
Have an actual texture.

Additional context
https://flexz.stackstorage.com/s/GUrHqR3OBGQZqhFa

I don't see anything problematic in the particular setup.
Do you still have the client logfile from when this happened?
Can you - when this happens again - submit your client logfile?

I've added a debug.log and latest.log in the folder edit1 to the url in the first message.
It happened again with the ME wireless access point on login this time.

ME controller, ME security terminal loaded this time.

Alright, found it:

[23Aug2020 13:23:26.434] [Server-Worker-9/WARN] [net.minecraft.client.renderer.model.ModelBakery/]: Unable to load model: 'appliedenergistics2:block/wireless_access_point_on' referenced from: appliedenergistics2:wireless_access_point#state=off: java.lang.IllegalStateException: Model loader 'appliedenergistics2:uvlightmap' not found. Registered loaders: immersiveengineering:conf_sides, immersiveengineering:ie_obj, appliedenergistics2:memory_card, appliedenergistics2:sky_compass, appliedenergistics2:facade, appliedenergistics2:part_plane, forge:obj, appliedenergistics2:quantum_bridge_formed, forge:item-layers, immersiveengineering:models/coresample, forge:bucket, appliedenergistics2:dummy_fluid_item, appliedenergistics2:crafting_cube, appliedenergistics2:drive, appliedenergistics2:glass, appliedenergistics2:encoded_pattern, immersiveengineering:connector, immersiveengineering:feedthrough, appliedenergistics2:color_applicator, forge:multi-layer, appliedenergistics2:p2p_tunnel_frequency, appliedenergistics2:biometric_card, appliedenergistics2:spatial_pylon, forge:composite, minecraft:elements, appliedenergistics2:paint_splotches, immersiveengineering:models/conveyor, immersiveengineering:models/multilayer

p.s.: You should delete those files again in case they contain anything sensitive (They don't as far as I know, but just be safe)

Could you let me know where to find this log file?
I've did the F3+C think, that you will find on the url.

If the log file is missing i'll post an update when it happens again as well.

So please let me know where to look

It should be in your Minecraft or instance folder in the "logs" subfolder, and be called debug.log.

BTW: I think this is related to something that Forge changed in 1.16.1
Potentially I can derive a fix from that for this problem.

@Flexz9 Can you please report back if 7.0.2 changes the situation for you?

7.0.3 seems to be fixing it, both single and multiplayer are showing all textures.