pkg: sqlite error while executing sqlite open in file pkgdb.c:1126: unable to open database file

[Jos Chrispijn]

Dear group,

Apparently I have an issue when finalizing the ports with portmanager.

When I run this batch to update my ports:

portmaster -y --clean-distfiles
portmaster -y --clean-packages
portmaster -y --check-depends
portmaster -a

At the end or the update (everything goes well) I sometimes get this 
display:

--- cut ---

===>>> Returning to update check of installed ports
===>>> Update check of installed ports complete
pkg: sqlite error while executing sqlite open in file pkgdb.c:1126: 
unable to open database file
===>>> Done displaying pkg-message files
===>>> The following actions were performed:

< list with ports updates (successful) >

--- cut ---

I checked numerous solutions, but most of them refer to a solution done 
with the pkg command, while I am using portmaster to upgrade.

Can someone tell me how I can solve this issue without risking my ports 
collection being corrupted by some pkg command?

Thanks for your help!
Jos Chrispijn