EE1 to EE2 error on 2.1.4

Question

did everything as described in the docs on upgrading EE1 to EE2 and getting stuck around 2.1.4 and then this error comes up on the screen. How do I upgrade to 2.6.1 from 1.7.3 without getting this error?

A Database Error Occurred
Error Number: 1064

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '`wm_name` varchar(80), `wm_type` varchar(10) DEFAULT 'text', `wm_image_path` v' at line 3

ALTER TABLE `exp_member_groups` ADD `wm_id` int(4) UNSIGNED AUTO_INCREMENT, `wm_name` varchar(80), `wm_type` varchar(10) DEFAULT 'text', `wm_image_path` varchar(100), `wm_test_image_path` varchar(100), `wm_use_font` char(1) DEFAULT 'y', `wm_font` varchar(30), `wm_font_size` int(3) UNSIGNED, `wm_text` varchar(100), `wm_vrt_alignment` varchar(10) DEFAULT 'top', `wm_hor_alignment` varchar(10) DEFAULT 'left', `wm_padding` int(3) UNSIGNED, `wm_opacity` int(3) UNSIGNED, `wm_x_offset` int(4) UNSIGNED, `wm_y_offset` int(4) UNSIGNED, `wm_x_transp` int(4), `wm_y_transp` int(4), `wm_font_color` varchar(7), `wm_use_drop_shadow` char(1) DEFAULT 'y', `wm_shadow_distance` int(3) UNSIGNED, `wm_shadow_color` varchar(7), `id` int(10) UNSIGNED AUTO_INCREMENT, `upload_location_id` int(4) UNSIGNED DEFAULT '0', `title` varchar(255), `short_name` varchar(255) DEFAULT '', `resize_type` varchar(50) DEFAULT '', `width` int(10) DEFAULT '0', `height` int(10) DEFAULT '0', `watermark_id` int(4) UNSIGNED, `file_id` int(10) UNSIGNED AUTO_INCREMENT, `cat_id` int(10) UNSIGNED, `sort` int(10) UNSIGNED DEFAULT '0', `is_cover` char(1) DEFAULT 'n', `site_id` int(4) UNSIGNED DEFAULT '1', `rel_path` varchar(255), `status` char(1) DEFAULT 'o', `mime_type` varchar(255), `file_name` varchar(255), `file_size` int(10) DEFAULT '0', `field_1` text, `field_1_fmt` tinytext, `field_2` text, `field_2_fmt` tinytext, `field_3` text, `field_3_fmt` tinytext, `field_4` text, `field_4_fmt` tinytext, `field_5` text, `field_5_fmt` tinytext, `field_6` text, `field_6_fmt` tinytext, `metadata` mediumtext NULL, `uploaded_by_member_id` int(10) UNSIGNED DEFAULT '0', `upload_date` int(10), `modified_by_member_id` int(10) UNSIGNED DEFAULT '0', `modified_date` int(10), `file_hw_original` varchar(20), `can_admin_upload_prefs` CHAR(1) DEFAULT 'n' NOT NULL AFTER `can_admin_channels`

Filename: /home/user/admin/expressionengine/libraries/Smartforge.php

Line Number: 122

So I then remove all the new EE2 files and try and go back to EE1, I load my homepage and get this error:

Site Error: Unable to Load Site Preferences; Invalid Preference Data

Answer 1

Are the columns the script is trying to add to exp_member_groups already present, perhaps from an earlier aborted attempt at an upgrade?

Looks like that was the issue when someone posted a similar question on EllisLab forum.

You mentioned that you restored the files, but did you restore the database as well?