Problem for validate (5.8.1.2)

Hello,
I made the update this morning and now it is impossible to validate the reservations made on an event.
It seems that the command buttons (accept, reject etc …) have disappeared.

An idea to solve the problem?

Ps: here’s a screenshot of the problem
https://drive.google.com/file/d/1LDGA0-StnRV_PlHx36Ppq8wX0eFrOWpb/view?usp=sharing