Sam issue here. Absolutely annoying!

*** IMPORTANT ***

Once again Adobe has released a new update for Illustrator 2021 - 25.4.8 this time - and ONCE AGAIN they've not bothered to fix this bug.

I've just tried updating my Illustrator from version 25.4.5 to 25.4.8 on my Mac (which runs macOS Mojave 10.14.6), i.e. skipping versions 25.4.6 and 25.4.7, which we know have this bug.

The new version - 25.4.8 - STILL HAS THE SAME BUG.

So, to avoid this bug, REMAIN ON VERSION 25.4.5.

And don't say "Oh, you should upgrade your macOS". As a company we CAN'T DO THAT. We HAVE to stick with Mojave, for some VERY GOOD REASONS.

Clearly they haven't bothered to address it, otherwise they would have released version 25.4.7 with the bug fix included!

It's hardly surprising though, seeing as version 25.x is no longer current. Adobe are ruthless in paying lip-service to maintaining software that they deem to be "legacy".

Just one example - there's been a bug in Illustrator for more years than I care to remember, whereby sometimes if you rename an Artboard, the name change APPEARS to work, but if you close the document, the next time you reopen it, the name has reverted to what it was previously.

They've had years to fix this but have never bothered.

Subscription-based software & ludicrous yearly major upgrades - whether they're needed or not - never mind asked for - always act to the detriment of software quality control, more's the pity...

Thank you for that, David Becker. I was considering making that same update, until reading your message. Does anyone know if Adobe have even bothered to address this at all?

*** IMPORTANT ***

I've just tried updating my Illustrator from version 25.4.5 to 25.4.7 on my Mac (which runs macOS Mojave 10.14.6), i.e. skipping version 25.4.6, which we know has this bug.

Sorry to report that the new version - 25.4.7 - STILL HAS THE SAME BUG.

Poor show Adobe.

I have the same issue with DxfDwgfileformat.AIP not loading in Illustrator and I don't know how to fix this. It will not allow me to create an AI file format.

What a mess! Why did I press the update button like an idiot? Now this important function doesn't work here at all. Should I try to go back to the last Illustrator version via TimeMachine? Why can this happen?!

Error loading plugins. DxfDwgFileFormat.aip
Illustrator not opening correctly or opening files, on 2013 iMac, running Mojave 10.14.6

Same issue here too. 2013 iMac running Mojave 10.14.6. 25.4.6 now refuses to open correctly etc. Have re-installed 25.4.5 as needed for work, and cannot ford to wait for Adobe to fix this.
Anybody have any news or heard anything from Adobe etc regarding this issue yet?

I have the exact same issue since updating to 25.4.6 on a 2013 Mac pro running Mojave 10.14.6

The same things happens for me.

Once I updated Illustrator from version 25.4.5 to 25.4.6 on my Mac (which runs macOS Mojave 10.14.6) I get the "Error loading plugins. DxfDwgFileFormat.aip" dialogue box every time I launch the program.

Also the update has broken the entire workspace. Switching to Illustrator using Command-Tab (as I always do) only makes the panels I have docked to the right hand side of my screen visible. The rest of the program doesn't come to the foreground.

So no Application Frame, no Advanced Toolbar, and no menus.

This supposed minor update is a mess. I'll be reverting to version 25.4.5 immediately.

The same issue on MacPro, macOS Mojave 10.14.6.
After automatically updating Illustrator to version 25.4.6, the DxfDwgFileFormat.aip plugin cannot be loaded.

I'm unable to open or export files as dxf or dwg formats due to error loading plugin. i'm using 64-bit operating system, x64-based processor Windows 10 Pro computer. i have tried reinstalling illustrator, but shows the same error. Please Help.
I have even tried using the adobe clean-up tool and installing illustrator again, but still get the same error.