[Qgis-user] editing shapelayer doesnt work

[info at architekten.coop]

dear qgis users

i use qgis 2.18.5 on windows 7

i converted datas of format dwg ( autocad) to shape file, with program 
cad2shape 4.0
then i builded in qgis a shapelayer an added two more columns and filled 
up the features,
all works fine. after all, i saved as qgis project.

after closing qgis and restarting the projectfile, i could no more 
change the editing status of the layer,
to work with the features, the whole digitizing toolbar was inactive.

thank you for any help

matthias moser