cannot install add ons, error -203, does not uninstall extensions with red !
updated firefox to 3.6.13 (problem still exists)
..error console says;
e.location.getitemlocation(e.id) is null
file:///c:/Program***/nsExtensionManager.js
updated firefox to 3.6.13 (problem still exists)
..error console says;
e.location.getitemlocation(e.id) is null
file:///c:/Program***/nsExtensionManager.js
Opaite Mbohovái (2)
Not A problem I have come across personally but I did notice this http://kb.mozillazine.org/Unable_to_install_themes_or_extensions#Unexpected_installation_error_-203
It would appear possible causes may include problems or blocking relating to security software, or corrupt files Hope it helps.
i had this issue also... but once i looked into it calmly and logically it turned out i was trying to install an add on for a future version of firefox.
my example is i was trying to install fireftp for firefox 4 but i only had firefox version 3.0...
could be a similar issue for others...?