When creating a trigger chain job you note that the job does not run unless you reduce the count of jobs present in the trigger chain.
In theory, there should be no limitation to the total number of jobs in a single trigger chain job as long as the criteria for trigger chain jobs are met such as the appropriate number of WSRETRY jobs.
However you may notice that some trigger chain jobs do not run as expected unless you reduce the total number of jobs in the trigger chain. Yet, other trigger chain jobs will run with the same number of jobs or more as part of the job's configuration.
This can happen due to the character limit imposed by the externalconnection column in the ecmimportjob table.
This column has a limitation of datatype varchar(255).
When the trigger chain is set to run, an entry for the trigger chain job will be written to the ecmimportjob table. All of the individual job names that are a part of the chain are combined into a single string with a comma separating job names and ##Continue appended to the end of the string.
That string of text is then written to the externalconnection column inside the ecmimportjob table as part of the entry for the trigger chain job. Therefore if the total number of characters in this string, including commas and ##Continue, exceeds anything more than 255 characters the job will not be able to insert the string of text, and the job will not proceed.
This string is 314 characters in total. This string cannot be inserted into the externalconnection column and the job entry will not be written to the ecmimportjob table. The job will not run.
If you large number of jobs in the chain then get first copy each name to a text file. Add a comma between each job name and append ##Continue to the end of the string. Count the total number of characters in the string. If it exceeds 255 characters in total the trigger chain job will fail to run.
If this character limit is exceeded then reduce the number of jobs in the trigger chain or rename jobs with shorter names.