LHC@home

no slot 0 there presently (I may have deleted it yesterday ...

This left the wrong entry in the vbox configuration file.

vm_image.vdi with preceeding acclamation mark

Remove this entry (it is useless since the img file doesn't exist any more).


Downgrade...Upgrade...Downgrade...Upg...
This usually causes additional problems.
At least you may not spend too much time in investigating errors that happened to active tasks during that phase.
Nobody might be able to reproduce/explain them.
Instead stay on a distinct version environment for a few cycles - OS, BOINC, vbox, subprojects, ...

[quote]vm_image.vdi with preceeding acclamation mark

Remove this entry (it is useless since the img file doesn't exist any more).

Removal of this entry in the VB Media Manager obviously was the key for solving the problem :-)
3 Theory tasks have now been running concurrently for a few hours :-)

Since I am NOT a VB specialist, I did not even know about the existence of the Media Manager and hence did not look into it before. How do we say: one never stops learning :-)

I now installed the 8GB "dual ranks" RAM, now having 16GB total, and everything runs fine.
Although I am sure that the source of my problem was not the second "single ranks" RAM, but the remaining and undetected entry "vm_image.vdi with preceeding acclamation mark" in the VB media manager, as described in my above postings.