Notice: Trying to get property of non-object in feeds_tamper_ui_form_feeds_ui_mapping_form_alter with beta4 and feeds-dev

I think you can work around this by disabling overlay (drush dis overlay) and the tamper plugins / fields are then visible. That said, I still can't get my taxonomy terms to import so I may be incorrect

Same here. When I'm on the Feeds Importer's Mapping page and I click on Configure Feeds Tamper, I get an empty main screen. It didn't help to disable overlay (through the Modules page).

Goal was to import Übercart product data (nodes) that contain hierarchical taxonomical data.

I uninstalled and deleted the recommended current version of Feeds Tamper, and installed the newest dev version (feeds_tamper-7.x-1.0-beta4+7-dev). Problem gone! The Feeds Tamper link has moved to a tab.

The latest dev is a tab, should have a new release soon.

I had the same problem until I updated beta-4 to the current dev version (using Feeds alpha-6).

I get the same problem with beta4...

Actualy it is fine if I click on tamper in the list of feeds, but if I click on feeds tamper in the cartography page, I get the error.
I think this link on the cartography page should be gone with beta4, but I desinstalled and reinstalled feeds tamper, it is still here...

@vregouby: this should be fixed in the next version (-beta5?). You can always download the -dev version if you can't wait anymore ...

@MrHarold. Thanks a lot for the update. Now that I know which link to use, it's not really an issue any more. I'll wait for the next beta5 version.

Better title, and status for finding this issue.
The solution is : update to feeds tamper dev-version.

patch suggestion temp fix

The patch #11 fixes the problem when you use new dev version from 2013-May-12.
Thanx, deltahex!

This issue reemerges after updating to the May 11th dev release. I tried running the patch in #11 but it said: patch: **** Only garbage was found in the patch input.

using latest dev worked for me without any patches

I can confirm: the error doesn't appear with the latest dev.

Confirmed: just used the latest dev version to get rid of the error. Thanks

feeds_tamper-7.x-1.x-dev works fine. And yes new tab is on the Feeds page
Edit | Export | Clone | Delete | Tamper
(not mapping like it used to be)

Confirming also that the latest DEV version gets rid of the error.

I had the same error using the version 7.x-1.0-beta4

Easy to resolve
Line 136 just change

$form['help']['#markup'] .= l(t('Configure Feeds Tamper'), FEEDS_TAMPER_UI_BASE . '/list/' . $form['#importer']->id);

to

$form['help']['#markup'] .= l(t('Configure Feeds Tamper'), FEEDS_TAMPER_UI_BASE . '/list/' . $form['#importer']);

Done, it's working like a charm !

@MacSim

Thank you a lot! Works here too now.

@MacSim

Worked for me too. I suggest submitting this patch as a fix

Like said before a couple of times: this is already fixed a long time ago.