Hi - using JMS 1.2.62. I get the following error when I try to uninstall an extension in a slave site:

Warning: require_once(/xxx/xxx/xx/xx/html/administrator/components/com_multisites/libraries/joomla/installer/adapters16/module.php) [function.require-once]: failed to open stream: No such file or directory in /xx/xx/xx/xx/html/administrator/components/com_multisites/libraries/joomla/installer/installer_multisites.php on line 592

Fatal error: require_once() [function.require]: Failed opening required '/xx/xx/xx/xx/html/administrator/components/com_multisites/libraries/joomla/installer/adapters16/module.php' (include_path='.:/usr/local/php5/lib/php') in /xx/xx/xx/xx/html/administrator/components/com_multisites/libraries/joomla/installer/installer_multisites.php on line 592

I've replaced my actual directory path with the xx above. The strange thing is that I do have the module.php file in the correct location, but my adapters directory is named adapters, not adapters16.

No problem at all uninstalling extensions from the master site. No problems installing extensions on a slave site either. Suggestions? Thanks in advance.

Such error were fixed in JMS 1.2.63.
So get the latest version that is currently the 1.2.66
See FAQ for the procedure to get the latest version.
www.jms2win.com/en/faq/faq-joomla-multi-sites

For your information, you can also uninstall module with the JMS Tool menu.
In this case, you select the slave site and after in the "module" tabs, you select the action "uninstall".

Yes, updating to 1.2.63 fixed it. Thanks.