To reproduce, create a "Simple calculated" question as follows:

• Write "{a}" in "Question text"
• Write "{a}/2" in "Answer 1 formula"
• Set Grade to 100% in "Answer 1"
• Click "Find the wild cards {x..} present in the correct answer formula
• Click on "Generate" 1 new set of waild card(s) values

What you get is:

    Can't find data record in database.

Debug info:

SELECT q.id, qc.id as category, q.parent, q.name, q.questiontext, q.questiontextformat,

q.generalfeedback, q.generalfeedbackformat, q.defaultmark, q.penalty, q.qtype,

q.length, q.stamp, q.timecreated, q.timemodified,

q.createdby, q.modifiedby, qbe.idnumber,

qc.contextid,

qv.status,

qv.id as versionid,

qv.version,

qv.questionbankentryid

FROM {question} q

JOIN {question_versions} qv ON qv.questionid = q.id

JOIN {question_bank_entries} qbe ON qbe.id = qv.questionbankentryid

JOIN {question_categories} qc ON qc.id = qbe.questioncategoryid

WHERE q.id = :id

[array (

'id' => 0,

)]

Error code: invalidrecordunknown

The stack trace:

• line 1674 of /lib/dml/moodle_database.php: dml_missing_record_exception thrown
• line 624 of /question/engine/bank.php: call to moodle_database->get_record_sql()
• line 587 of /cache/classes/loaders.php: call to question_finder->load_for_cache()
• line 1792 of /cache/classes/loaders.php: call to cache->get_implementation()
• line 405 of /cache/classes/loaders.php: call to cache_application->get_implementation()
• line 480 of /question/engine/bank.php: call to cache->get()
• line 255 of /question/engine/bank.php: call to question_finder->load_question_data()
• line 273 of /question/engine/bank.php: call to question_bank::load_question_data()
• line 217 of /question/bank/editquestion/question.php: call to question_bank::load_question()