Woocommerce PHP error

Since updating to Woocommerce 2.3.13 the following error message (always 3 lines) is regularly logged in the error log file:
[27-Jul-2015 13:54:24 UTC] PHP Notice: Trying to get property of non-object in /home/boardsc/public_html/wp-content/plugins/woocommerce/includes/class-wc-form-handler.php on line 583
[27-Jul-2015 13:54:24 UTC] PHP Notice: Trying to get property of non-object in /home/boardsc/public_html/wp-content/plugins/woocommerce/includes/class-wc-form-handler.php on line 586
[27-Jul-2015 13:54:24 UTC] PHP Notice: Trying to get property of non-object in /home/boardsc/public_html/wp-content/plugins/woocommerce/includes/class-wc-form-handler.php on line 586

We also get out of memory errors regularly such as:
[27-Jul-2015 08:14:30 UTC] WordPress database error MySQL client ran out of memory for query SELECT t.*, tt.*, tr.object_id FROM wp_terms AS t INNER JOIN wp_term_taxonomy AS tt ON tt.term_id = t.term_id INNER JOIN wp_term_relationships AS tr ON tr.term_taxonomy_id = tt.term_taxonomy_id WHERE tt.taxonomy IN (‘product_brand’, ‘product_type’, ‘product_cat’, ‘product_tag’, ‘product_shipping_class’, ‘pa_volume’, ‘pa_size’, ‘pa_production-year’, ‘pa_colour’, ‘pa_sup-size’, ‘pa_fin-size’, ‘pa_windsurf-bag-size’, ‘pa_mast-length’, ‘pa_rope-length’, ‘pa_fin-bolt-length’, ‘pa_sail-size’, ‘pa_boom-length’, ‘pa_mast-bend’, ‘pa_kids-size’, ‘pa_fin-box’, ‘pa_foot-size’, ‘pa_construction’, ‘pa_line-length’, ‘pa_batten-length’, ‘pa_washer-size’, ‘pa_general-length’, ‘pa_diameter’, ‘pa_multi-buy’, ‘pa_mast-extension-length’, ‘pa_north-ibase-system’, ‘pa_mast-type’, ‘pa_surf-board-size’, ‘pa_kayak-package’, ‘pa_kite-board-size’, ‘pa_kite-size’, ‘pa_rig-options’, ‘pa_junior-rig-size’) AND tr.object_id IN 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8383, 2259, 1953, 1975, 1773, 1774, 1522, 1523, 8364, 8389, 8348, 6300, 1785, 2052, 1789, 8292, 2220, 1583, 2217, 8393, 1852, 6251, 6264, 7374, 2397, 9278, 1558, 9260, 1777, 5159, 8238, 8006, 5062, 5085, 5082, 5080, 8410, 804, 5565, 5277, 8711, 805, 8412, 8418, 806, 4309, 5524, 655, 8339, 8594, 8619, 2344, 2410, 8631, 8645, 8655, 8658, 8610, 8608, 807, 8596, 7945, 266, 8612, 2352, 7942, 9366, 900, 8650, 8624, 808, 8636, 8622, 809, 810, 8606, 8668, 8652, 811, 8732, 8497, 8500, 485, 2845, 505, 504, 502, 503, 487, 7335, 488, 572, 5414, 5399, 489, 599, 501, 490, 3221, 3246, 5807, 494, 492, 5341, 497, 9303, 506, 9298, 853, 904, 901, 7932, 5531, 902, 903, 3709, 3703, 3742, 3713, 3714, 3737, 3707, 3716, 3727, 3699, 1162, 3665, 812, 7506, 1163, 813, 814, 9333, 2966, 7342, 7741, 7725, 7839, 7712, 7733, 7718, 7068, 6882, 5952, 4648, 5755, 5909, 7000, 7581, 5999, 6036, 6916, 7866, 8018, 8013, 7269, 815, 2450, 817, 2975, 905, 7524, 2279, 816, 1998, 818, 819, 7273, 2456, 3747, 3748, 262, 2423, 2435, 2416, 2429, 7964, 2348, 5491, 1779, 1769, 2222, 1770, 1771, 3378, 507, 3006, 7642, 1833, 2337, 508, 2055, 1799, 5485, 5535, 1956, 7434, 8570, 3175, 5444, 5450, 9187, 9180, 5176, 511, 5317, 821, 8659, 8124, 656, 2473, 2486, 664, 665, 667, 670, 672, 675, 677, 680, 685, 7892, 7236, 5103, 5008, 5100, 1987, 822, 6447, 1996, 2459, 3204, 3215, 3208, 3195, 3242, 3229, 3250, 3253, 7882, 8082, 3569, 3553, 8334, 2846, 823, 2850, 2843, 907, 3575, 824, 4345, 4350, 4335, 4339, 825, 2844, 826, 827, 2842, 2936, 4373, 4331, 2928, 2932, 2933, 1153, 3626, 5636, 3483, 4466, 4130, 5283, 4158, 1319, 397, 3767, 1321, 3772, 783, 1322, 1329, 3777, 773, 1324, 1525, 720, 7931, 829, 830, 1966, 1980, 3020, 1155, 1156, 1838, 1979, 7484, 1157, 831, 513, 514, 515, 405, 1299, 1310, 408, 1313, 1300, 409, 1301, 1302, 1303, 410, 1304, 411, 1305, 1298, 1312, 1307, 1316, 1390, 832, 9220, 4083, 8053, 8030, 3935, 8240, 9307, 9166, 2447, 8255, 8262, 516, 833, 1731, 1737, 6064, 3182, 1071, 5499, 7621, 1717, 1999, 2008, 5695, 5706, 6764, 6783, 5012, 5055, 5064, 5029, 8185, 5022, 5048, 5041, 5034, 8717, 2601, 2605, 2403, 3323, 3304, 3298, 3335, 5460, 3329, 9205, 2048, 2073, 3317, 3338, 3268, 3281, 2175, 2181, 3310, 6854, 6860, 3344, 2604, 835, 836, 9403, 837, 838, 4291, 839, 840, 841, 842, 843, 7888, 844, 1168, 1169, 1170, 1171, 5603, 5607, 6074, 846, 847, 848, 7266, 849, 850, 4825, 1180, 851, 852, 5883, 854, 7279, 2634, 855, 856, 6456, 857, 858, 859, 860, 861, 5624, 4294, 5366, 1172, 1173, 6437, 834, 5248, 2876, 2872, 862, 4933, 2852, 1989, 1991, 5110, 6433, 2868, 863, 4937, 2860, 2864, 2880, 906, 864, 865, 866, 3017, 867, 868, 2640, 869, 3153, 5076, 6594, 2110, 5116, 6526, 6560, 2115, 8797, 8802, 8800, 8805, 4982, 4986, 4988, 4995, 4990, 4999, 6187, 6639, 6496, 6614, 2134, 6658, 2129, 8734, 8579, 6086, 6687, 6690, 4059, 4075, 4044, 4066, 6680, 531, 532, 300, 534, 5901, 2603, 1166, 7486, 870, 4954, 4957, 1802, 4352, 4344, 2284, 8598, 3167, 2963, 3061, 3054, 3067, 3140, 3147, 3097, 3085, 3091, 3022, 3129, 3029, 3154, 2289, 2295, 2331, 2338, 8662, 2937, 7405, 2941, 7419, 2956, 5388, 3021, 4098, 694, 7457, 7972, 3798, 3844, 3802, 3815, 4012, 3984) ORDER BY t.name ASC made by require(‘wp-blog-header.php’), wp, WP->main, WP->query_posts, WP_Query->query, WP_Query->get_posts, update_post_caches, update_object_term_cache, wp_get_object_terms
[27-Jul-2015 08:14:30 UTC] PHP Fatal error: Out of memory (allocated 83886080) (tried to allocate 72 bytes) in /home/boardsc/public_html/wp-includes/taxonomy.php on line 3853
[27-Jul-2015 08:14:30 UTC] PHP Fatal error: Unknown: Cannot use output buffering in output buffering display handlers in Unknown on line 0
[27-Jul-2015 08:14:30 UTC] PHP Fatal error: Out of memory (allocated 74711040) (tried to allocate 24 bytes) in /home/boardsc/public_html/wp-includes/class.wp-dependencies.php on line 221
[27-Jul-2015 08:14:30 UTC] PHP Fatal error: Out of memory (allocated 63963136) (tried to allocate 81 bytes) in /home/boardsc/public_html/wp-includes/pomo/mo.php on line 238
[27-Jul-2015 08:14:30 UTC] PHP Fatal error: Out of memory (allocated 22806528) (tried to allocate 122880 bytes) in /home/boardsc/public_html/wp-content/plugins/cleantalk-spam-protect/cleantalk-public.php on line 136

This occurred when editing a product.

Here is system status information:
WordPress Environment
Home URL: [?] https://4boards.co.uk
Site URL: [?] https://4boards.co.uk
WC Version: [?] 2.3.13
WC Database Version: [?] 2.3.13
Log Directory Writable: [?] ? /home/boardsc/public_html/wp-content/uploads/wc-logs/
WP Version: [?] 4.2.3
WP Multisite: [?] –
WP Memory Limit: [?] 512 MB
WP Debug Mode: [?] ?
Language: [?] en_GB
Server Environment
Server Info: [?] Apache
PHP Version: [?] 5.3.29 – We recommend a minimum PHP version of 5.4. See: How to update your PHP version
PHP Post Max Size: [?] 60 MB
PHP Time Limit: [?] 500
PHP Max Input Vars: [?] 1000
SUHOSIN Installed: [?] ?
MySQL Version: [?] 5.6.23
Max Upload Size: [?] 2 MB
Default Timezone is UTC: [?] ?
fsockopen/cURL: [?] ?
SoapClient: [?] ?
DOMDocument: [?] ?
GZip: [?] ?
Remote Post: [?] ?
Remote Get: [?] ?
Server Locale
decimal_point: [?] .
thousands_sep: [?] N/A
mon_decimal_point: [?] N/A
mon_thousands_sep: [?] N/A
Active Plugins (19)
Breadcrumb NavXT by John Havlik – 5.2.2
Anti-spam by CleanTalk by СleanTalk – 5.17
Configure SMTP by Scott Reilly – 3.1
Contact Form 7 by Takayuki Miyoshi – 4.2.1
Fluid Video Embeds by jamie3d – 1.2.7
Google Analytics Dashboard for WP by Alin Marcu – 4.8.1.2
Previous and Next Post in Same Taxonomy by Bill Erickson – 1.0
Regenerate Thumbnails by Viper007Bond – 2.2.4
Revolution Slider by ThemePunch – 4.1.3
Ultimate Coming Soon Page by SeedProd – 1.14.4
WooCommerce Brands by WooThemes – 1.3.3
WooCommerce Sequential Order Numbers by SkyVerge – 1.4.0
WooCommerce Table Rate Shipping by Mike Jolley – 2.9.0
WooCommerce by WooThemes – 2.3.13
WooCommerce SagePayCw by customweb GmbH – 3.0.2
WooThemes Helper by WooThemes – 1.5.9
Yoast SEO by Team Yoast – 2.3.1
WP-Memory-Usage by Alex Rabe – 1.2.2
YITH WooCommerce Wishlist by Yithemes – 2.0.8