Roland updated the CutStudio plugin to fix the problem outlined in this post. Update to the latest (of this writing) version 2.02 for the fixed certificate (see below for explanation if you're curious). I have personally tested this plugin and it does indeed work, mitigating the ugly workaround outlined below. If/When in the future this error crops back up, the instructions below should still work to fix the problem.
Software downloads: http://download.rolanddg.jp/en/cutting.html#cutstudiopinwin
Around March 17th of 2021, the CutStudio plugin stopped working for everybody in Illustrator CS6.
I have a client who called me out with the error "Invalid Signature Extension" which I later discovered was because they removed the plugin from the Adobe Extension Manager, however the problem still remained that the CutStudio plugin for Illustrator CS6 stopped working and the client couldn't get the plugin to re-install in Adobe Extension Manager.
I remembered running into a similar situation a few years ago and found that dealt with the timestamp of the plugin. In that situation, the CutStudio plugin was outdated and upgrading to the latest version 2.02 solved the problem. Fast forward to March 17th and the problem started back up with the last CutStudio version available for Illustrator CS6.
For my particular client and I'm sure in your situation too, you've paid for Illustrator CS6, you're using it to cut to one or a handful of plotters and you don't want to spend money every year on the stupid expensive fancy latest-and-greatest Adobe suite because what you have works "just fine". It's totally relatable and nobody can blame you, especially when Roland tends to be on the slow side of getting their plugins up-dated with the latest versions of the Adobe software and you run into problems with it every few years... We all just want something that works. And when it breaks for some other reason, we'll update it then, Am I right?
Alright, let's dig into the simple instructions on getting you back up and running with CutStudio and Illustrator CS6.
What I found when digging into the CutStudio plugin package was that it was officially set to expire as of March 16th, 2021. Adobe requires anyone who makes plugin packages to create a certificate which helps protect the package from being tampered with. Certificates require a signing date and this date just-so-happened to be March 16th, 2021 for the CutStudio plugin.
When the signature timestamp expires, in this case 11:59 PM March 16th, 2021, the plugins stop working.
For anyone wishing to dig into the certificate itself, I've extracted it for you.
x509 Signature Certificate
Decoding the certificate at https://www.sslshopper.com/certificate-decoder.html gives:
Common Name: Roland DG Corporation Organization: Roland DG Corporation Organization Unit: Roland DG Corporation Country: JP Valid From: March 15, 2016 Valid To: March 16, 2021 Issuer: Roland DG Corporation, Roland DG Corporation Serial Number: 2d36306463363032333a31353338323033643262613a2d38303030
I would love to say that Roland will update the plugin with a new certificate, but don't hold your breath. I will be very surprised if Roland releases a new plugin for Illustrator CS6 to add a new certificate. Don't worry though because I found a pretty solid workaround that seems to not only do the trick, but should help future proof the plugin.
If the plugin is still installed in the Adobe Extension Manager, then proceed to the Illustrator Workaround
1) Download the latest CutStudio plugin extension for Illustrator CS6 (latest version as of this blog post is 2.02)
2) Extension Manager
a) Open Adobe Extension Manager
b) Before installing the plugin, disable the signature and administrator checks and click OK
c) Install the plugin and ignore the warnings that pop up. (They are telling you the signature is expired etc.)
In order to use the plugin with Illustrator, the workaround is to trick Adobe into always thinking it is running BEFORE March 17, 2021.
1) Download Time Stopper: https://www.raymond.cc/blog/download/did/1781/
2) Extract Time Stopper using raymondcc as the password
3) Install Time Stopper
4) Run Time Stopper and set it up like the image
a) Set the path to illustrator.exe as: C:\Program Files\Adobe\Adobe Illustrator CS6\Support Files\Contents\Windows (unless it's different on your computer)
b) Set a date to March 16th 2021 or earlier
c) In the shortcut box, type Illustrator CS6 and click the Create desktop short-cut button
d) Click Exit to close Time Stopper
5) Use the new shortcut on the desktop to launch Adobe Illustrator CS6. This is important because the new shortcut holds all of the information to set the date back. If you still have and try to use the original shortcut icon or you try to use the start menu to launch Illustrator, it won't work. It has to be the one created by TimeStopper.
All done! The plugin should work just fine now because Illustrator thinks it is running on a date that is before the CutStudio Plugin expires.
This won't affect the timestamp on files when you save them either. (I checked) Save files will continue to use the most current date.