Please help us help you and fill where relevant:
Your LimeSurvey version: 6.1.2 / 6.1.3 (master)
Own server or LimeSurvey hosting: own server
Survey theme/template: default
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We have used LimeSurvey for few years and wanted to upgrade it to the newest version: 6.1.2
Unfortunately we encountered problem with attaching files to survey's e-mail templates.

The problem exists on our web server with our database and even in local Docker version with demo records.
I tested LimeSurvey in Docker with PHP 8.2 and 7.4

For the demo purpose I had created new survey, which got id 275838, and then I went to link:
limesurvey-demo.loc/index.php/admin/emai...ndex/surveyid/275838

File manager loads correctly from time to time (see attached screenshots) in Firefox.
In Google Chrome it can cause tab crash.

Files can be successfully uploaded, but I cannot choose them and attach below the form (by double click or choosing Select from the context menu).

Have you experienced such strange behaviour?

I cannot see any errors in JavaScript console.

PHP 8.2 is not supported - manual.limesurvey.org/Installation_-_Lim...rvey_on_your_website