I just started right now a new project in Intellij using Spring Boot ver 2.1.3 and Flyway 5.2.4 with Java 11.
After try to start my project i got :
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It is not that much useful or accurate answer.
But This issue make you frustrated so that i give this solution.
Note: Strange but it's true, Sometime it's not allow copy paste because your folder created db.migration and it expact db->migration(It's not same in this scenario). So whenever you start from scratch. Go to the resource folder -> Create DB folder -> Create migration folder -> Create database file with Version_SubVersion__Name(As defined below).
Normally this happens in following cases,
In my case i already place sql file over there but still it gives same error, Basically i place this sql file using copy paste from somewhere.
When i try to add one new file on same place using IDE (Intellij : Right click on migration folder -> new -> Flyway migration -> versioned migration), then it ask me(warning) about some delicate allowance(normally we mention in database configuration i also place there still), and it start working.