Multiterm 2019, cannot fix a constant bug

Dear all,

I cannot open my TBs, here is what looks this bug alike, I have got the same repeated message with all my TBs:

I found some proposals in the forum which advise to use SDL FreshStart.

I installed SDL FreshStart, but there was something even more strange that happened,: when I try to use the function "Remove folders from following locations: ",

SDL FreshStart tells me that... Multiterm is currently running, which is absolutely false (??):

I really don't know what to do right now, do you have any hint?

Thanks in advance,