Error on testing connection in IDT

Hello,

I got a BI 4.1 SP03 over SBO. Connection is to MS SQL 12.

got a strange error while trying to create measure inside IDT, after a while that evertyhing was working fine.

Continued the 'investigation'  and found out the connection in the BO to the DB fails - while pressing "EDIT" on the connection and pressing "Test" inside the popup - succeed.

The file attached is the error I get while creating a measure on IDT.

Webi working fine, dashboards working fine. data is coming from DB fine. only IDT and DS runs into error (same error in all actions)

Couldn't find in similar case around - anyone have any idea?

Thank you,

Or.