Knowledge Base

Problem

A user opens an EthoVision experiment file in a newer version of the software (e.g., XT 18) — even briefly or accidentally in analysis mode — and subsequently cannot reopen the file in the older version (e.g., XT 17).

Details

EthoVision upgrades the internal database format of an experiment file the first time it is opened in a newer version. This is a one-way conversion: the file is permanently marked as belonging to the newer version and will display a critical error or incompatibility warning if opened in an older version. This can happen even when the user does not have a license for the newer version, because EthoVision can be run in unlicensed analysis mode. Affects any version transition, reported specifically for XT 17 → XT 18.

Solution

1. The converted file cannot be downgraded back to the older version format. This is by design.
2. To continue working with the experiment, install and use the newer version of EthoVision (XT 18 or whichever version converted the file).
3. If a valid license for the newer version is not available, contact Noldus Sales to obtain or upgrade the license.
4. To prevent this in future: do not open experiment files in a newer version of EthoVision unless you intend to permanently migrate to that version. Keep separate installation directories if multiple versions must coexist.
5. If the file was only recently converted and a backup exists from before the conversion, restore from backup to recover the older-format file.