SCORM 2004 Packages can have objectiveID's as text/string type and not necessary int.
The ADL SCORM 2004 Test packages have objectiveID as a string value in the imsmanifest.xml file. The objectvieid field in prefix_scorm_seq_objective table has type bigint(10), due to which while adding objectiveid to the scorm_seq_objective table a dml_write_exception is thrown.
The imsmanifest.xml file for test package CM-02a can be found here - https://github.com/mayankgupta/moodle_scorm_test_harness/blob/master/ADL2004/LMSTestCoursePackageSrc/LMSTestPackage_CM-02a/imsmanifest.xml

To reproduce this issue follow the steps -
1. Download the ADL SCORM Test packages CM-02a or CM-02b or CM-03a. You can download them from here - https://github.com/mayankgupta/moodle_scorm_test_harness/tree/master/ADL2004/LMSTestCourseZipPackages
2. Add these SCORM package as activity inside a course.
3. Fill in the instructions and save the
4. You will come across the error - "Error writing to database"
5. If you have debugging turned on you would get the following debug info

Debug info: Incorrect integer value: 'obj1' for column 'objectiveid' at row 1
INSERT INTO mdl_scorm_seq_objective (scoid,primaryobj,objectiveid,minnormalizedmeasure) VALUES(?,?,?,?)
[array (
0 => 88,
1 => 0,
2 => 'obj1',
3 => 1,
)]
Stack trace:
line 397 of \lib\dml\moodle_database.php: dml_write_exception thrown
line 878 of \lib\dml\mysqli_native_moodle_database.php: call to moodle_database->query_end()
line 920 of \lib\dml\mysqli_native_moodle_database.php: call to mysqli_native_moodle_database->insert_record_raw()
line 590 of \mod\scorm\datamodels\scormlib.php: call to mysqli_native_moodle_database->insert_record()
line 238 of \mod\scorm\locallib.php: call to scorm_parse_scorm()
line 119 of \mod\scorm\lib.php: call to scorm_parse()
line 410 of \course\modedit.php: call to scorm_add_instance()