Now it works well. Thank you so much Martin! Have a nice weekend.

Hello. Thanks for your answer. I updated the license but it doesnt help. The issue is the same.

I started the video push the pause button and wait from 20 to 30 seconds. And the error begins. Its not nessesary to pause the video. It may works 30 seconds and get error again.

Here is the screencast of error – https://youtu.be/vmQLGZjdHug
Here is my site example page – https://kursi.club/lessons/urok-1-zakony-linejnoj-perspektivy-obratnaja-perspektiva/

### Begin System Info ###

## Please include this information when posting support requests ##

Multisite:                No

SITE_URL:                 https://kursi.club
HOME_URL:                 https://kursi.club
Plugin URL:               https://kursi.club/wp-content/plugins/fv-wordpress-flowplayer

FV Player version:        7.4.37.727
FV Player core version:   7.2.7
FV Player license:        Valid (next check 2020-12-02 14:16:33 GMT)

FV Player Pro version:    7.4.36.727
FV Player Pro license:    Valid (next check 2020-12-02 14:16:32 GMT)

WordPress Version:        5.5.3
Permalink Structure:      /%postname%/
Active Theme:             BuddyBoss Theme 1.6.0

Browser:                  Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.66 Safari/537.36
PHP Version:              7.4.11
MySQL Version:            5.5.5
Web Server Info:          nginx/1.18.0

WordPress Memory Limit:   40M
PHP Memory Limit:         256M
PHP Upload Max Size:      50M
PHP Post Max Size:        50M
PHP Upload Max Filesize:  50M
PHP Time Limit:           300
PHP Max Input Vars:       3000
PHP Arg Separator:        &
PHP Allow URL File Open:  Yes
WP_DEBUG:                 Disabled

DISPLAY ERRORS:           On (off)
cURL:                     Your server supports cURL.

ACTIVE PLUGINS:

BuddyBoss Platform: 1.5.5.1
BuddyPress User Profile Tabs Creator Pro: 1.2.3
FV Player: 7.4.37.727
FV Player Pro: 7.4.36.727
Hide Title: 1.0.8
Jetpack by WordPress.com: 9.0.2
LearnDash LMS: 3.2.3.5
Real Media Library: 4.10.0
UpdraftPlus - Backup/Restore: 2.16.31.24
Users Insights: 3.9.2
WishList Member™: 3.7.7338
Wordfence Security: 7.4.12
WP Mail SMTP Pro: 2.5.0
WP Tao: 1.2.10
WP Translitera: p1.2.5

SETTINGS

Array
(
    [nag_fv_player_7] => 1
    [notice_new_lightbox] => 1
    [notice_db] => 1
    [notice_xml_sitemap_iframes] => 1
    [autoplay] => false
    [googleanalytics] => 
    [chromecast] => true
    [key] => (redacted)
    [logo] => 
    [rtmp] => 
    [auto_buffering] => false
    [disableembedding] => true
    [disablesharing] => true
    [disable_video_hash_links] => true
    [popupbox] => false
    [allowfullscreen] => true
    [allowuploads] => true
    [postthumbnail] => false
    [tgt] => backgroundcolor
    [backgroundColor] => #333333
    [canvas] => #000000
    [sliderColor] => #ffffff
    [durationColor] => #eeeeee
    [timeColor] => #eeeeee
    [progressColor] => #bb0000
    [bufferColor] => #eeeeee
    [timelineColor] => #666666
    [borderColor] => #666666
    [hasBorder] => false
    [adTextColor] => #888888
    [adLinksColor] => #ff3333
    [subtitleBgColor] => rgba(0,0,0,0.50)
    [subtitleSize] => 16
    [playlistBgColor] => #808080
    [playlistFontColor] => #
    [playlistSelectedColor] => #bb0000
    [logoPosition] => bottom-left
    [parse_commas] => false
    [width] => 640
    [height] => 360
    [engine] => false
    [font-face] => Tahoma, Geneva, sans-serif
    [ad] => 
    [ad_width] => 0
    [ad_height] => 0
    [ad_css] => .wpfp_custom_ad { position: absolute; bottom: 10%; z-index: 20; width: 100%; }
.wpfp_custom_ad_content { background: white; margin: 0 auto; position: relative }
    [ad_show_after] => 0
    [disable_videochecker] => true
    [interface] => Array
        (
            [ads] => false
            [align] => false
            [autoplay] => false
            [controlbar] => false
            [embed] => false
            [mobile] => false
            [playlist_advance] => false
            [playlist] => false
            [playlist_captions] => false
            [share] => false
            [speed] => true
            [splash_text] => false
            [subtitles] => false
            [sticky] => false
            [synopsis] => false
            [end_actions] => false
            [lightbox] => false
            [ab] => false
            [popup] => true
        )

    [amazon_bucket] => Array
        (
            [0] => 
        )

    [amazon_key] => (redacted, 1)
    [amazon_secret] => (redacted, 1)
    [amazon_region] => Array
        (
            [0] => 
        )

    [amazon_expire] => 5
    [amazon_expire_force] => false
    [fixed_size] => false
    [js-everywhere] => false
    [marginBottom] => 28
    [ui_play_button] => true
    [volume] => 0.7
    [player-position] => 
    [playlist_advance] => true
    [sharing_email_text] => Check out the amazing video here
    [liststyle] => horizontal
    [ui_speed_increment] => 0.5
    [popups_default] => no
    [email_lists] => Array
        (
            [#fv_list_dummy_key#] => Array
                (
                    [title] => 
                    [description] => 
                    [first_name] => 0
                    [last_name] => 0
                    [disabled] => 0
                )

            [0] => Array
                (
                    [title] => 
                    [description] => 
                    [first_name] => 0
                    [last_name] => 0
                    [disabled] => 0
                )

            [1] => Array
                (
                    [title] => Subscribe to list one
                    [description] => Two good reasons to subscribe right now
                    [first_name] => 1
                    [last_name] => 0
                    [disabled] => 0
                )

        )

    [sticky_video] => false
    [sticky_place] => right-bottom
    [sticky_width] => 380
    [playlist-design] => 2017
    [skin-slim] => Array
        (
            [progressColor] => #bb0000
            [accent] => #4682B4
        )

    [skin-youtuby] => Array
        (
            [progressColor] => #bb0000
            [accent] => #4682B4
        )

    [skin-custom] => Array
        (
            [hasBorder] => false
            [bottom-fs] => false
            [borderColor] => #666666
            [marginBottom] => 2.8
            [bufferColor] => #eeeeee
            [canvas] => #000000
            [backgroundColor] => rgba(51,51,51,1.00)
            [font-face] => Tahoma, Geneva, sans-serif
            [player-position] => 
            [progressColor] => #bb0000
            [timeColor] => #eeeeee
            [durationColor] => #eeeeee
            [design-timeline] =>  
            [design-icons] =>  
            [accent] => #4682B4
        )

    [skin] => slim
    [hlsjs] => true
    [lightbox_images] => false
    [lightbox_improve_galleries] => false
    [mailchimp_api] => 
    [mailchimp_list] => 
    [mailchimp_label] => Subscribe for updates
    [version] => 7.4.37.727
    [css_writeout-https-kursi-club] => 
    [pro] => Array
        (
            [quality] => ,
            [transcript_theme] => light
            [video_ads_default] => no
            [video_ads_postroll_default] => no
            [video_ads_skip] => 5
            [video_ads_skip_minimum] => 10
            [watching_prompt_msg] => Вы еще здесь? Если да, пошевелите мышью :)
            [interface] => Array
                (
                    [chapters] => false
                    [copy_text] => false
                    [hflip] => false
                )

            [autoplay_once] => false
            [start_end] => false
            [autoplay_scroll] => false
            [ab_loop] => false
            [vimeo_debug] => true
            [copy_text] => false
            [copy_text_time] => 5
            [watching_prompt] => false
            [watching_prompt_interval] => 1
            [transcript_hidden] => false
            [download_template] => %caption%
            [download_no_right_click] => false
            [vimeo] => false
            [yt_logo] => true
            [youtube_ads_disable] => true
            [youtube_key] => (redacted)
            [amazon_s3] => false
            [cf_domain] => 
            [cf_key_id] => 
            [cf_pk] => 
            [elastic_key] => 
            [elastic_secret] => 
            [elastic_region] => 
            [bunnycdn_domain] => 
            [bunnycdn_secure_token] => (redacted)
            [keycdn_domain] => 
            [keycdn_secure_token] => (redacted)
            [stackpath_domain] => 
            [stackpath_secure_token] => (redacted)
            [ads_exoclick_zone] => 
            [ads_exoclick_login] => 
            [ads_exoclick_cat] => 
            [ads_exoclick_site] => 
            [video_ads_between_vids] => false
            [video_ads_once] => false
            [video_ads] => Array
                (
                )

            [autoplay_scroll_enhanced] => false
            [cloudflare_domain] => 
            [cloudflare_secure_token] => (redacted)
            [stream_loader_on] => false
            [stream_loader_speed_up] => false
            [display_preset] => flash
            [separate_subtitle_disabling] => false
        )

    [video_model_db_checked] => 7.4.37.727
    [video_meta_model_db_checked] => 7.4.37.727
    [player_model_db_checked] => 7.4.37.727
    [fv-wp-flowplayer-submit] => SaveAllChanges
    [show_controlbar] => false
    [hd_streaming] => false
    [multiple_playback] => false
    [ui_no_picture_button] => false
    [ui_repeat_button] => false
    [ui_rewind_button] => false
    [ui_speed] => true
    [splash] => https://kursi.club/wp-content/uploads/2020/10/FON.png
    [subtitleOn] => false
    [video_position_save_enable] => true
    [integrations] => Array
        (
            [featured_img] => false
            [wp_core_video] => true
            [facebook_sharing] => false
            [schema_org] => false
        )

    [css_disable] => true
    [profile_videos_enable_bio] => false
    [parse_comments] => false
    [rtmp-live-buffer] => false
    [db_duration] => false
    [lightbox_force] => false
    [mobile_native_fullscreen] => true
    [mobile_force_fullscreen] => true
    [mobile_alternative_fullscreen] => true
    [mobile_landscape_fullscreen] => true
    [video_sitemap] => false
    [video_sitemap_meta] => 
    [fv_player_admin_pro_quality_alive] => 1
    [playlistFontColor-proxy] => #
    [subtitleFontFace] => inherit
    [s3_browser] => false
    [fv_player_admin_pro_video_ads_alive] => 1
    [vi_login] => 
    [vi_pass] => 
    [player_meta_model_db_checked] => 7.4.37.727
    [msg] => 
    [digitalocean_spaces] => Array
        (
            [space] => 
            [endpoint] => 
            [key] => 
            [secret] => 
        )

    [video_checker_agreement] => true
    [wistia_use_fv_player] => false
)

DATABASE

CREATE TABLE `wp_fv_player_players` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
  `player_name` varchar(255) COLLATE utf8mb4_unicode_ci NOT NULL,
  `player_slug` varchar(255) COLLATE utf8mb4_unicode_ci NOT NULL,
  `videos` text COLLATE utf8mb4_unicode_ci NOT NULL,
  `ab` varchar(3) COLLATE utf8mb4_unicode_ci NOT NULL,
  `ad` text COLLATE utf8mb4_unicode_ci NOT NULL,
  `ad_height` varchar(7) COLLATE utf8mb4_unicode_ci NOT NULL,
  `ad_width` varchar(7) COLLATE utf8mb4_unicode_ci NOT NULL,
  `ad_skip` varchar(7) COLLATE utf8mb4_unicode_ci NOT NULL,
  `align` varchar(7) COLLATE utf8mb4_unicode_ci NOT NULL,
  `author` bigint(20) unsigned NOT NULL DEFAULT 0,
  `autoplay` varchar(7) COLLATE utf8mb4_unicode_ci NOT NULL,
  `controlbar` varchar(7) COLLATE utf8mb4_unicode_ci NOT NULL,
  `copy_text` varchar(120) COLLATE utf8mb4_unicode_ci NOT NULL,
  `changed_by` bigint(20) unsigned NOT NULL DEFAULT 0,
  `date_created` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
  `date_modified` datetime NOT NULL DEFAULT '0000-00-00 00:00:00',
  `embed` varchar(12) COLLATE utf8mb4_unicode_ci NOT NULL,
  `end_actions` varchar(10) COLLATE utf8mb4_unicode_ci NOT NULL,
  `end_action_value` varchar(255) COLLATE utf8mb4_unicode_ci NOT NULL,
  `height` varchar(7) COLLATE utf8mb4_unicode_ci NOT NULL,
  `hflip` varchar(7) COLLATE utf8mb4_unicode_ci NOT NULL,
  `lightbox` varchar(7) COLLATE utf8mb4_unicode_ci NOT NULL,
  `lightbox_caption` varchar(120) COLLATE utf8mb4_unicode_ci NOT NULL,
  `lightbox_height` varchar(7) COLLATE utf8mb4_unicode_ci NOT NULL,
  `lightbox_width` varchar(7) COLLATE utf8mb4_unicode_ci NOT NULL,
  `playlist` varchar(10) COLLATE utf8mb4_unicode_ci NOT NULL,
  `playlist_advance` varchar(7) COLLATE utf8mb4_unicode_ci NOT NULL,
  `qsel` varchar(25) COLLATE utf8mb4_unicode_ci NOT NULL,
  `share` varchar(7) COLLATE utf8mb4_unicode_ci NOT NULL,
  `share_title` varchar(120) COLLATE utf8mb4_unicode_ci NOT NULL,
  `share_url` varchar(255) COLLATE utf8mb4_unicode_ci NOT NULL,
  `speed` varchar(255) COLLATE utf8mb4_unicode_ci NOT NULL,
  `sticky` varchar(7) COLLATE utf8mb4_unicode_ci NOT NULL,
  `video_ads` varchar(10) COLLATE utf8mb4_unicode_ci NOT NULL,
  `video_ads_post` varchar(10) COLLATE utf8mb4_unicode_ci NOT NULL,
  `width` varchar(7) COLLATE utf8mb4_unicode_ci NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2932 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci

CREATE TABLE `wp_fv_player_playermeta` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
  `id_player` bigint(20) unsigned NOT NULL DEFAULT 0,
  `meta_key` varchar(255) COLLATE utf8mb4_unicode_ci NOT NULL,
  `meta_value` longtext COLLATE utf8mb4_unicode_ci NOT NULL,
  PRIMARY KEY (`id`),
  KEY `id_player` (`id_player`),
  KEY `meta_key` (`meta_key`(191))
) ENGINE=InnoDB AUTO_INCREMENT=2966 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci

CREATE TABLE `wp_fv_player_videos` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
  `src` varchar(1024) COLLATE utf8mb4_unicode_ci NOT NULL,
  `src1` varchar(1024) COLLATE utf8mb4_unicode_ci NOT NULL,
  `src2` varchar(1024) COLLATE utf8mb4_unicode_ci NOT NULL,
  `splash` varchar(1024) COLLATE utf8mb4_unicode_ci NOT NULL,
  `splash_text` varchar(1024) COLLATE utf8mb4_unicode_ci NOT NULL,
  `caption` varchar(1024) COLLATE utf8mb4_unicode_ci NOT NULL,
  `end` varchar(1024) COLLATE utf8mb4_unicode_ci NOT NULL,
  `mobile` varchar(1024) COLLATE utf8mb4_unicode_ci NOT NULL,
  `rtmp` varchar(1024) COLLATE utf8mb4_unicode_ci NOT NULL,
  `rtmp_path` varchar(1024) COLLATE utf8mb4_unicode_ci NOT NULL,
  `start` varchar(1024) COLLATE utf8mb4_unicode_ci NOT NULL,
  PRIMARY KEY (`id`),
  KEY `src` (`src`(191)),
  KEY `caption` (`caption`(191))
) ENGINE=InnoDB AUTO_INCREMENT=2932 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci

CREATE TABLE `wp_fv_player_videometa` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
  `id_video` bigint(20) unsigned NOT NULL DEFAULT 0,
  `meta_key` varchar(255) COLLATE utf8mb4_unicode_ci NOT NULL,
  `meta_value` longtext COLLATE utf8mb4_unicode_ci NOT NULL,
  PRIMARY KEY (`id`),
  KEY `id_video` (`id_video`),
  KEY `meta_key` (`meta_key`(191))
) ENGINE=InnoDB AUTO_INCREMENT=60 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci

### End System Info ###