id,summary,reporter,owner,description,type,status,priority,milestone,component,resolution,keywords,cc,workpackage 1064,"""Fitting did not converge!!!"" error with a Sum|Multi plugin model",smk78,,"Reported by User alessandra.delgiudice@uniroma1.it: Dear SASview developer, I found problems making fits with Sum|Multi plugin models in the 4.1.2 version. In brief: In the 4.1.2 version I got a ""Fitting did not converge!!!"" error, whereas trying with the 4.1 version (installed on the same pc in a different folder) the fit worked. I did a test with simulated data: I created a Sum|Multi model with the dedicated tool: sphere_plus_hollowcylinder.py I saved a calculated curve with parameters: p1_scale 0.5 p1_background 0 p1_sld 9.45 p1_sld_solvent 9.4 p1_radius 100 p2_scale 0.5 p2_background 0 p2_radius 50 p2_thickness 20 p2_length 1000 p2_sld 9.45 p2_sld_solvent 9.4 scale_factor 1 and 1400 points as sphere_and_hollow_cylinder_out.txt I loaded this file as a data file to be fitted. I changed the sphere radius value from 100 to 50, and then clicked to ""Fit"". Nothing happened and I got a ""Fitting did not converge!!!"" error in the console. I had an older installation file for SASview 4.1 and I installed it on my laptop in the folder SasView_4_1 instead of !SasView (where the 4.1.2 version is) The same test worked in this case. When trying a similar test with a simpler model (sphere with default parameters), the fit starting from a different value of the sphere radius (100 instead of 50) worked with the 4.1.2 version. I attach the sasview log as sasview_20180112.log. What I described starts with the line ""2018-01-12 11:50:05,181 INFO --- !SasView session started ---"" ",defect,closed,critical,SasView 4.2.0,SasView,fixed,,,SasView Bug Fixing