# CSV imports fail - stalling In Progress, Runtime Less than 1 second **URL:** \ **Category:** Product Support\ **Tags:** mautic-4\ **Created:** [August 27, 2022, 4:11pm UTC](https://forum.mautic.org/t/csv-imports-fail-stalling-in-progress-runtime-less-than-1-second/25199 "2022-08-27T16:11:53Z")\ **Posts on this page:** 1\ **Showing post:** 6
**Author:** ![modifiedcontent](https://sea2.discourse-cdn.com/flex020/user_avatar/forum.mautic.org/modifiedcontent/32/511_2.png) [@modifiedcontent](https://forum.mautic.org/u/modifiedcontent)\ **Post date:** [September 2, 2022, 5:49pm UTC](https://forum.mautic.org/t/csv-imports-fail-stalling-in-progress-runtime-less-than-1-second/25199/6 "2022-09-02T17:49:20Z")
[In this case](https://forum.mautic.org/t/4-2-cant-send-email-error-500-foreign-key-constraint-fails/22933/9) a failing foreign key constraint was apparently caused by an encoding mismatch. Almost all of the tables in my database had collation utf8\_unicode\_ci. A few had utf8mb4\_unicode\_ci; I have converted those to utf8\_unicode\_ci and will test later if that made any difference… What else could I check? Is there a way to safely “reset” the tables that cause these problems? Or does the ‘integrity constraint violation’ point to another problem - what problem does it point to? **Edit:** I am now converting all tables to utf8mb4\_unicode\_ci, [following this recipe to fix the general foreign key mess](https://github.com/mautic/mautic/issues/9129). Using `alter table lead_event_log CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;`, I get the following unusual error: > #1025 - Error on rename of ‘./mydatabase/#sql-a26\_721a’ to ‘./mydatabase/lead\_event\_log’ (errno: 150 “Foreign key constraint is incorrectly formed”) Same error on tables oauth2\_accesstokens, oauth2\_clients, oauth2\_refreshtokens, users, … Several other tables, like plugin\_citrix\_events, have this error: > Specified key was too long; max key length is 3072 bytes Does anyone know what this means? --- _[View the full topic](https://forum.mautic.org/t/csv-imports-fail-stalling-in-progress-runtime-less-than-1-second/25199)._