Firefox Extension troubleshooting

Note: You need to use at least Firefox version 52.0 to perform browser automations.

This topic presents the most frequent reasons why the UiPath Extension for Firefox might not work properly, and how to solve these issues.

Extension on older Firefox versions

Description

Mozilla introduced an extension signing verification algorithm in Firefox, which disables add-ons for Firefox version 65.0 and lower. As such, if you install the UiPath Extension for Firefox on the browser version 65.0 or lower, the following error message is displayed:

This add-on could not be installed because it appears to be corrupt.

Solution 1

Update Firefox to version v66.0.4 or higher.

Solution 2

Starting with Studio 2020.8, the Firefox extension is newly signed and it should be properly installed on older versions of the Firefox browser.

Checking the extension

Check if the UiPath Extension for Firefox is installed and enabled:

1. In Mozilla Firefox, go to about:addons > Extensions.
2. If the extension is not present, install it as explained here.
3. Make sure the UiPath Extension is updated to the latest version.

To prevent possible issues:

1. In Mozilla Firefox, go to about:addons > Extensions.
2. Open Task Manager or Process Explorer.
3. Check if the ChromeNativeMessaging.exe process is running.
   Note: A separate ChromeNativeMessaging instance is running for the Chrome extension, so you need to close Google Chrome when performing this check.

If ChromeNativeMessaging is not running:

1. In Mozilla Firefox, go to about:addons > Extensions.
2. Remove the UiPath extension manually by clicking the Remove button.
3. Reinstall it as explained here.

In case the above information did not solve your issue, you can try getting additional information by viewing traces and analyzing the errors thrown by the UiPath extension. The following are types of traces you can collect and analyze:

For the general extension traces in Mozilla Firefox:

Go to Open menu > Web Developer > Browser Console (Ctrl+Shift+J). The Browser Console is displayed. All the errors generated by the extension are displayed here.

For traces generated by the web page you want to automate:

Go to Open menu> Web Developer > Web Console (Ctrl+Shift+K). The Web Console is displayed. All the errors for the current web page are displayed here.

For full traces, (not only errors) do the following:

1. Open the Registry Editor.
2. Navigate to the HKEY_CURRENT_USER\SOFTWARE\UiPath key.
3. Double-click the WebExtensionTrace REG_DWORD value. The Edit DWORD Value window is displayed.
4. In the Value Data field, change the value to 1, and click OK. The value is saved.
   Note: If the WebExtensionTrace REG_DWORD value does not exist, you have to create it, by right-clicking the right panel, selecting New > DWORD (32-bit) Value, and providing the values mentioned above.

Check if there is some data missing in the Registry Editor:

1. Open the Registry Editor.
2. Navigate to the HKEY_CURRENT_USER\SOFTWARE\Mozilla\NativeMessagingHosts\com.uipath.chromenativemsg key.
3. Open the (Default) REG_SZ value. The Edit String window is displayed and should contain a path similar to C:\Users\YOUR_USER_NAME\AppData\Local\UiPath\uipath-ff.json.
4. Open the .json file at the path found above with a text editor, such as Notepad++.
5. Check that the path property correctly points to where ChromeNativeMessaging.exe is located, similar to C:\Program Files (x86)\UiPath Studio\UiPath\BrowserExtension\ChromeNativeMessaging.exe.