- Plesk for Linux
During a Plesk upgrade to Plesk Obsidian 18.0.37, the following error is shown:
PLESK_INFO: ERROR: Upgrade step 2021-07-01-11-34-45_TrimPlanNames.php failed with code 255 and output:
PHP Fatal error: Uncaught JMS\Serializer\Exception\RuntimeException: Could not decode JSON, syntax error - malformed JSON. in /usr/local/psa/admin/plib/vendor/jms/serializer/src/JsonDeserializationVisitor.php:240
If update is not possible for some reason you may try the following
The error may be safely ignored.