My version 1.50 after one week is just fine with no updates. Maybe someone could investigate it what is going on with updates.

I miss some content from ArmA 2. That is all. Anyway no patch was downloaded today so it looks promising with that "read only" parameter.

I atteched two .RPT files for comparison. Yesterday I changed "read only" and today I did not get that 900MB update but for sure I will wait few days before I can be sure about it.

I am using HDD and it is installed in different drive than Steam application but I have it this way installed from alpha version two years ago without problems until now. Yes Arma 3 folder is read only but on the other hand all folders of games in common are read only with out issues.

Thanks for quick response. I tried verify game cache with 0 bytes downloaded so nothing has been downloaded. Well it seems my installation is not corrupted. This issue anyway occur only when I start up my PC then it gets latest update as it should but not every day the same update and then at first start of the game it crashes with error above. Second and other starts of the game are OK.