UIM 9.0 and earlier
snmpcollector 3.43 and earlier
Templates had duplicate ID values.
each template must have a unique ID value.
If you have multiple templates with the same the editor fails to open.
Edit the tempate files in <nimsoft>/probes/network/snmpcollector/bulk_config/templates
Review the fisrt 5 lines of each 8.tplt file and make sure the ideas are all different:
"version" : 2,
"id" : "168ce551-b59c-42c1-Bc70-50e02153e595",
"name" : "Xilinx PAN 1 Devices",
"description" : "This is the Default Template automatically applied to all juniper devices",