I am not able to update extensions in my slave sites. When trying to install over an existing extension, after clicking the Upload & Install button in Extension Manager > Install, I get a white page with the following error message:

Catchable fatal error: Argument 1 passed to AtsystemUtilExceptionshandler::__construct() must be an instance of JRegistry, instance of Joomla\Registry\Registry given, called in /home/myaccount/domains/master.com/subdomains/network/public_html/plugins/system/admintools/admintools/main.php on line 310 and defined in /home/myaccount/domains/master.com/subdomains/master/public_html/plugins/system/admintools/util/exceptionshandler.php on line 18

I contacted the developer of Admin Tools and this is what he said:

"Something is broken on your site. Even though Joomla! replaced the JRegistry class with Joomla\Registry\Registry it registers a class alias. The error you are receiving means that this alias is not registered which is NOT what normally happens with Joomla! 3.4.3 under any supported PHP version (5.3.10 to 5.6). Therefore I have to say that something must be broken on your site."

Please advise on how this can be fixed?

I'm running Joomla 3.4.3, JMS is the latest version 1.3.53 FULL, PHP 5.4.43

Thanks!

As you are using the latest JMS 1.3.53, I suggeset that you send us the "Admin tootl" that you are using in the attachement of an email to help try reproducing that.

I've sent the extension installer for Admin Tools to you via Skype. I'd really like to do a TeamViewer tech session with you today to fix this, asap. Because of this problem, I cannot update any extensions in my slave sites. On another slave site, a locator extension called Store Locator is not working because I cannot update it.

I sent you some info via Skype. Ping me there when you have some time.

Thanks for the JMS update, Edwin! The latest version, which includes the updated JMS patch, appears to have resolved the problem and I am now able to install and update extensions without the above mentioned error.