Phorum Database Error

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Error:

Table './phorum/phorum_users' is marked as crashed and should be repaired (145): SELECT * FROM phorum_users WHERE user_id IN (40349, 40419, 40253, 40354, 40849, 40783, 40721, 38669, 40536, 40116, 40071, 40407, 40380, 40317, 40285, 40094, 40126)

Backtrace:

Function phorum_database_error called at
{path to Phorum}/include/db/mysql/mysqli.php:212
----
Function phorum_db_interact called at
{path to Phorum}/include/db/mysql.php:3217
----
Function phorum_db_user_get called at
{path to Phorum}/include/api/user.php:934
----
Function phorum_api_user_get called at
{path to Phorum}/include/api/user.php:1122
----
Function phorum_api_user_get_display_name called at
{path to Phorum}/include/feed_functions.php:22
----
Function phorum_feed_make_rss called at
{path to Phorum}/feed.php:137
----