After updating to v5.4.2, the import process throws a fatal error when the Thumbnail field contains structured data that was previously exported by STEC itself. This data worked in earlier versions. The plugin appears to now misinterpret the field as a timezone.

Environment:

• STEC Calendar plugin Version: 5.4.2 (just updated today)

• WordPress: latest stable

• PHP: 7.4+

• OS/Web Host: Ubuntu 20.04 / Apache

Symptoms:

• Export to CSV or iCal

  • Triggers a “There has been a critical error on this website” message (see screenshot)

  • No file is generated

Import from CSV

• Shows “Sorry, something went wrong” banner

• Network response JSON reports:

{
  "code":"qm_fatal",
  "message":"Uncaught Exception: DateTimeZone::__construct(): Unknown or bad timezone ({"type":"date","icon":"fa-solid fa-calendar","image":[]}) …",
  "data":{ … }
}

When the timezone field is not in play, the thumbnail field causes the same error to be thrown.

Impact:

• Cannot back up, migrate, or bulk‑update events

• Blocks all CSV/iCal import and export workflows for the STEC calendar

Hi! I just tried to import again and this file (attached) uploaded fine, so the other file I was trying to upload must have formatting issues that I will address.

However, the Export function is still giving 'There has been a critical error on this website.' 

This error happens regardless of the number of events I am trying to export. This is a new phenomenon since upgrading to v5.4.2 yesterday. Earlier in the day I was able to export with no issue.