Since Minyaa has been fully refactorised, to upgrade from Minyaa 3.x to Minyaa 4.0, an upgrade to JIRA 6.4.12 with Minyaa 3.5.2 will be mandatory.
You will have to process as follow :
jira-plugin-minyaa-boot-6.4.6-3.5.2.jar
jira-plugin-minyaa-core-6.4.6-3.5.2.jar
jira-plugin-minyaa-i18n-default-3.5.2.jar
jira-plugin-minyaa-i18n-de_DE-3.5.2.jar
jira-plugin-minyaa-i18n-en_US-3.5.2.jar
jira-plugin-minyaa-i18n-fr_FR-3.5.2.jar
jira-plugin-minyaa-i18n-pl_PL-3.5.2.jar
jira-plugin-minyaa-i18n-ru_RU-3.5.2.jar
jira-plugin-minyaa-i18n-tr_TR-3.5.2.jar
jira-plugin-minyaa-i18n-uk_UA-3.5.2.jar
jira-plugin-minyaa-reports-6.4.6-3.5.2.jar
jira-plugin-minyaa-workflows-6.4.6-3.5.2.jar
jira-plugin-minyaa-tools-6.4.6-3.5.2.jar
jira-plugin-minyaa-time-reports-6.4.6-3.5.2.jar
jira-plugin-minyaa-time-6.4.6-3.5.2.jar
jira-plugin-minyaa-spread-6.4.6-3.5.2.jar
dwr-2.0.5.jar
truexml-1.29.jar
truelicense-1.29.jar
minyaa-license-manager-1.12.jar
At this stage, the previous Listeners and Service of Minyaa 3.5.x have been upgraded to the new version.
At the moment, there is no automatic migration process for upgrading to the new Minyaa Gadgets.
You will have to perform them by yourself.