bash-5.0$ ./upgrade/upgrade.sh

Starting Camunda Optimize Upgrade to 3.0.0...



================================ WARNING! ================================

Please be aware that you are about to upgrade the Optimize data
schema in Elasticsearch from version 2.7.0 to 3.0.0.
There is no warranty that this upgrade might not break the data
structure in Elasticsearch. Therefore, it is highly recommended to
create a backup of your data in Elasticsearch in case something goes wrong.

Do you want to proceed? [(y)es/(n)o]

1. (y)es = I already did a backup and want to proceed.
2. (n)o = Thanks for reminding me, I want to do a backup first.

Your answer (type your answer and hit enter): y

Execute upgrade...
06:19:24.408 - Starting step 1/9: UpdateIndexStep
06:19:24.499 - request [PUT http://elasticsearch-master:9200/_template/optimize-event_v2?master_timeout=30s] returned 1 warnings: [299 Elasticsearch-7.6.2-ef48eb35cf30adf4db14086e8aabd07ef6fb113f "The [nGram] tokenizer d will be removed in a future version. Please change the tokenizer name to [ngram] instead."]
06:19:24.794 - request [PUT http://elasticsearch-master:9200/optimize-event_v2-000001?master_timeout=30s&timeout=30s] returned 1 warnings: [299 Elasticsearch-7.6.2-ef48eb35cf30adf4db14086e8aabd07ef6fb113f "The [nGram] tecated and will be removed in a future version. Please change the tokenizer name to [ngram] instead."]
06:19:24.878 - Reindexing from optimize-event_v1 to optimize-event_v2-000001, progress: 0%. Reindex status= total: 0, updated: 0, created: 0, deleted: 0
06:19:26.066 - Error while executing upgrade from 2.7.0 to 3.0.0
java.lang.NullPointerException: null
        at org.camunda.optimize.upgrade.steps.schema.UpdateIndexStep.execute(UpdateIndexStep.java:71)
        at org.camunda.optimize.upgrade.plan.UpgradeExecutionPlan.execute(UpgradeExecutionPlan.java:88)
        at org.camunda.optimize.upgrade.main.UpgradeProcedure.performUpgrade(UpgradeProcedure.java:33)
        at org.camunda.optimize.upgrade.main.UpgradeMain.main(UpgradeMain.java:62)