I have create custom CRS for my project. That's one of local CRS for Russia - MSK-72 / zone 1. Parameters are: +proj=tmerc +lat_0=0 +lon_0=66.08333333 +k=1 +x_0=1500000 +y_0=-6000000 +ellps=krass +towgs84=23.57,-140.95,-79.8,0,0.35,0.79,-0.22 +units=m +no_defs. After switching project CRS to this one custom, all layers on my map are located on correct places. I've also reprojected layers to custom CRS. After reloading the project, layers still in correct position, but CRS both for project and for all layers is indicated as UNKNOWN. How can I fix this error?
My own solution for this problem was: - Set custom CRS with parameters given in Proj String; - reload file and get an Unknown CRS in project or layer properties; - make sure parameters of this Unknown CRS are given in WKT; - copy WKT parameters and past it while creating new custom CRS;
This new one CRS with parameters given in WKT works good and not disappearing after reloading the priject.