The "Accounts.frm" file is missing or does not have the correct user permissions. The file is located at <Controller_Home>/db/data/eum_db/accounts.frm.
If the file is located in the proper path, the problem is a permissions issue.
To resolve the error, enter the following command in the terminal for the Controller host to change the ownership of the file to the correct user and group. For example, the user/group through which the Controller was installed.
Then restart the EUM-processor to resolve the issue.