We have upgraded CMS from Web 8.1 to Web 8.5 couple of months back. We got three CMS nodes behind the F5, We frequently used to see below list of issues and restarting Content Manager Service Host solves the problem and may happen again after 1 week in that node. At least one node per week shows us this behavior.
List of issues:
Unable to see thumbnails of images inside components.
Used to see below error while page previews or version history comparison etc., in CME.
(80040356) Could not load file or assembly '0 bytes loaded from Tridion.ContentManager.Templating, Version=126.96.36.1996, Culture=neutral, PublicKeyToken=360aac4d3354074b' or one of its dependencies. An attempt was made to load a program with an incorrect format. Bad IL format.
Bad IL format.
Unable to see thumbnails in CME media repository (which are ECL from S3)
We are not seeing any bad CPU or memory metrics in that particular node at the time of failure.
So i am looking for some guidance on how to investigate this?