Devonthink pro office slow in starting

Recently I have noticed that my database (not too big) takes minutes to load. Devonthink hangs for quite a while on «Loading Plug-Ins». Is there a solution to speed a little the opening of a database?
Thanks

Reboot?

Run verify & repair to catch possible problems in the database.

Are you on 10.11? Beach balls are very common for me on that release.

Yes I am on El Capitan (10.11.2). I have run verify etc, but with no changes.
As I said the software hangs (on starting it up) on a specific moment: on «Loadings plug-ins».
Thanks anyway.

Try reinstalling the DEVONthink Pro Office Apple Mail Plugin.

Quit Mail. Quit DEVONthink. Navigate to ~/Library/Mail/Bundles and move DEVONMailConduit-SnowLeopard.mailbundle to the Desktop. Start DEVONthink. In DEVONthink > Install Add-Ons… click the Apple Mail Plugin and click Install. Launch Mail again.

If you are using other mail bundles like Spam Sieve, Mail Tags, etc., that have not been upgraded for Mail 9.2 (OS X 10.11) they could be causing conflicts that affect DEVONthink. Not likely – but you might want to disable those if you continue to have trouble and see if there are upgrades from those developers.

Also, if you have database set to Sync onOpen (see the middle pane in Preferences > Sync), this could cause the app to pause.

Thank you Korm: your solution solved my issue!
Have a wonderful day.