Call error stack: On widget use

Hello and first of all thanks a lot for this incredible plugin!!!

We have been using it for a while on our website without any issue but I encounter a problem on the new version that I am developing on a local server (WAMP).

When I try to include the widget in any of my sidebars, I get the following message:

In C:\wamp\www\allnewish\wp-content\plugins\transposh-translation-filter-for-wordpress\widgets\default\tpw_default.php on line 51
Call Stack
# Time Memory Function Location
1 0.0003 251152 {main}( ) ..\index.php:0
2 0.0005 254688 require( ‘C:\wamp\www\allnewish\wp-blog-header.php’ ) ..\index.php:17
3 0.3324 26109408 require_once( ‘C:\wamp\www\allnewish\wp-includes\template-loader.php’ ) ..\wp-blog-header.php:16
4 0.3460 26468568 include( ‘C:\wamp\www\allnewish\wp-content\themes\twentyfourteen-child\single.php’ ) ..\template-loader.php:74
5 0.3460 26468760 get_header( ) ..\single.php:10
6 0.3460 26469456 locate_template( ) ..\general-template.php:47
7 0.3461 26469640 load_template( ) ..\template.php:477
8 0.3465 26499024 require_once( ‘C:\wamp\www\allnewish\wp-content\themes\twentyfourteen-child\header.php’ ) ..\template.php:501
9 0.3492 26513136 wp_head( ) ..\header.php:30
10 0.3492 26513248 do_action( ) ..\general-template.php:2030
11 0.3516 26520472 call_user_func_array ( ) ..\plugin.php:470
12 0.3516 26520504 wp_print_styles( ) ..\plugin.php:470
13 0.3517 26520720 do_action( ) ..\functions.wp-styles.php:34
14 0.3517 26522584 call_user_func_array ( ) ..\plugin.php:470
15 0.3517 26522664 transposh_plugin_widget->add_transposh_widget_css( ) ..\plugin.php:470
16 0.3519 26524792 transposh_plugin_widget->load_widget( ) ..\transposh_widget.php:171

I tryed various set-up, without allowing the translation to any user, allowing it to everybody, not pushing the js to the footer, reinstalling it manually… but the problem persists.

I hope you can help,
Many thanks in advance!!!
Tche’ers

https://ww.wp.xz.cn/plugins/transposh-translation-filter-for-wordpress/