Hello,
Sorry for slow response...
The issue is when updating for a too old release (before 3.2.14).
So, first
unzip 3.4.1. package
Then, go in
admin/sql/updates/3.2.14.sql
Edit the first line with this (to fix the issue introduced in 3.4.1, when updated all sql files in one click, with a mass replace) :
ALTER TABLE `#__icagenda` ADD COLUMN `params` TEXT NOT NULL DEFAULT '' AFTER `releasedate`;
The issue is the after not well placed.
So then, package your modified 3.4.1, and install it.
It should solve the issue!
Best Regards,
Cyril