In old versions of Kaamelot and Minyaa, the RegExp customfield associated native the Text fields with a new Searcher with same name : Free Text Searcher.

Impact in your configuration : you may have some fields defined with Minyaa Text Searcher.

Since 3.3.8, the association has been corrected. After installation, the native Text fields associated to Minyaa Text Fields will no more associated to a valid a Searcher, then not searchable.

You will have to restore the native Free Text Searcher to native Text Fields, by executing the following SQL Queries.

update customfield set customfieldsearcherkey = 'com.atlassian.jira.plugin.system.customfieldtypes:textsearcher' 
where customfieldsearcherkey =  'jira.plugin.minyaa.tools:textsearcher'
and customfieldtypekey in 
('com.atlassian.jira.plugin.system.customfieldtypes:textfield'
,'com.atlassian.jira.plugin.system.customfieldtypes:textarea'
,'com.atlassian.jira.plugin.system.customfieldtypes:readonlyfield')